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Li Y, Wang X, Meng Y, Hu T, Zhao J, Li R, Bai Q, Yuan P, Han J, Hao K, Wei Y, Qiu Y, Li N, Zhao Y. Dopamine reuptake and inhibitory mechanisms in human dopamine transporter. Nature 2024; 632:686-694. [PMID: 39112701 DOI: 10.1038/s41586-024-07796-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 07/05/2024] [Indexed: 08/16/2024]
Abstract
The dopamine transporter has a crucial role in regulation of dopaminergic neurotransmission by uptake of dopamine into neurons and contributes to the abuse potential of psychomotor stimulants1-3. Despite decades of study, the structure, substrate binding, conformational transitions and drug-binding poses of human dopamine transporter remain unknown. Here we report structures of the human dopamine transporter in its apo state, and in complex with the substrate dopamine, the attention deficit hyperactivity disorder drug methylphenidate, and the dopamine-uptake inhibitors GBR12909 and benztropine. The dopamine-bound structure in the occluded state precisely illustrates the binding position of dopamine and associated ions. The structures bound to drugs are captured in outward-facing or inward-facing states, illuminating distinct binding modes and conformational transitions during substrate transport. Unlike the outward-facing state, which is stabilized by cocaine, GBR12909 and benztropine stabilize the dopamine transporter in the inward-facing state, revealing previously unseen drug-binding poses and providing insights into how they counteract the effects of cocaine. This study establishes a framework for understanding the functioning of the human dopamine transporter and developing therapeutic interventions for dopamine transporter-related disorders and cocaine addiction.
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Affiliation(s)
- Yue Li
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Xianping Wang
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yufei Meng
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Tuo Hu
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jun Zhao
- Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences at Weifang, Weifang, China
| | - Renjie Li
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Qinru Bai
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Pu Yuan
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Jun Han
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Kun Hao
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yiqing Wei
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yunlong Qiu
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Na Li
- Heart Center and Beijing Key Laboratory of Hypertension, Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Yan Zhao
- Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
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2
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Ecevitoglu A, Meka N, Rotolo RA, Edelstein GA, Srinath S, Beard KR, Carratala-Ros C, Presby RE, Cao J, Okorom A, Newman AH, Correa M, Salamone JD. Potential therapeutics for effort-related motivational dysfunction: assessing novel atypical dopamine transport inhibitors. Neuropsychopharmacology 2024; 49:1309-1317. [PMID: 38429498 PMCID: PMC11224370 DOI: 10.1038/s41386-024-01826-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 01/28/2024] [Accepted: 02/05/2024] [Indexed: 03/03/2024]
Abstract
People with depression and other neuropsychiatric disorders can experience motivational dysfunctions such as fatigue and anergia, which involve reduced exertion of effort in goal-directed activity. To model effort-related motivational dysfunction, effort-based choice tasks can be used, in which rats can select between obtaining a preferred reinforcer by high exertion of effort vs. a low effort/less preferred option. Preclinical data indicate that dopamine transport (DAT) inhibitors can reverse pharmacologically-induced low-effort biases and increase selection of high-effort options in effort-based choice tasks. Although classical DAT blockers like cocaine can produce undesirable effects such as liability for misuse and psychotic reactions, not all DAT inhibitors have the same neurochemical profile. The current study characterized the effort-related effects of novel DAT inhibitors that are modafinil analogs and have a range of binding profiles and neurochemical actions (JJC8-088, JJC8-089, RDS3-094, and JJC8-091) by using two different effort-related choice behavior tasks in male Sprague-Dawley rats. JJC8-088, JJC8-089, and RDS3-094 significantly reversed the low-effort bias induced by the VMAT-2 inhibitor tetrabenazine, increasing selection of high-effort fixed ratio 5 lever pressing vs. chow intake. In addition, JJC8-089 reversed the effects of tetrabenazine in female rats. JJC8-088 and JJC8-089 also increased selection of high-effort progressive ratio responding in a choice task. However, JJC8-091 failed to produce these outcomes, potentially due to its unique pharmacological profile (i.e., binding to an occluded conformation of DAT). Assessment of a broad range of DAT inhibitors with different neurochemical characteristics may lead to the identification of compounds that are useful for treating motivational dysfunction in humans.
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Affiliation(s)
- Alev Ecevitoglu
- Psychological Sciences, University of Connecticut, Storrs, CT, 06269-1020, USA
| | - Nicolette Meka
- Psychological Sciences, University of Connecticut, Storrs, CT, 06269-1020, USA
| | - Renee A Rotolo
- Psychological Sciences, University of Connecticut, Storrs, CT, 06269-1020, USA
| | - Gayle A Edelstein
- Psychological Sciences, University of Connecticut, Storrs, CT, 06269-1020, USA
| | - Sonya Srinath
- Psychological Sciences, University of Connecticut, Storrs, CT, 06269-1020, USA
| | - Kathryn R Beard
- Psychological Sciences, University of Connecticut, Storrs, CT, 06269-1020, USA
| | - Carla Carratala-Ros
- Psychological Sciences, University of Connecticut, Storrs, CT, 06269-1020, USA
- Area de Psicobiología. Universitat Jaume I, Castelló, Spain
| | - Rose E Presby
- Psychological Sciences, University of Connecticut, Storrs, CT, 06269-1020, USA
| | - Jianjing Cao
- Medicinal Chemistry Section, NIDA-Intramural Research Program, Baltimore, MD, 21224, USA
| | - Amarachi Okorom
- Medicinal Chemistry Section, NIDA-Intramural Research Program, Baltimore, MD, 21224, USA
| | - Amy H Newman
- Medicinal Chemistry Section, NIDA-Intramural Research Program, Baltimore, MD, 21224, USA
| | - Mercè Correa
- Area de Psicobiología. Universitat Jaume I, Castelló, Spain
| | - John D Salamone
- Psychological Sciences, University of Connecticut, Storrs, CT, 06269-1020, USA.
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3
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Lee KH, Won SJ, Oyinloye P, Shi L. Unlocking the Potential of High-Quality Dopamine Transporter Pharmacological Data: Advancing Robust Machine Learning-Based QSAR Modeling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.06.583803. [PMID: 38558976 PMCID: PMC10979915 DOI: 10.1101/2024.03.06.583803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The dopamine transporter (DAT) plays a critical role in the central nervous system and has been implicated in numerous psychiatric disorders. The ligand-based approaches are instrumental to decipher the structure-activity relationship (SAR) of DAT ligands, especially the quantitative SAR (QSAR) modeling. By gathering and analyzing data from literature and databases, we systematically assemble a diverse range of ligands binding to DAT, aiming to discern the general features of DAT ligands and uncover the chemical space for potential novel DAT ligand scaffolds. The aggregation of DAT pharmacological activity data, particularly from databases like ChEMBL, provides a foundation for constructing robust QSAR models. The compilation and meticulous filtering of these data, establishing high-quality training datasets with specific divisions of pharmacological assays and data types, along with the application of QSAR modeling, prove to be a promising strategy for navigating the pertinent chemical space. Through a systematic comparison of DAT QSAR models using training datasets from various ChEMBL releases, we underscore the positive impact of enhanced data set quality and increased data set size on the predictive power of DAT QSAR models.
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Affiliation(s)
- Kuo Hao Lee
- Computational Chemistry and Molecular Biophysics Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Sung Joon Won
- Computational Chemistry and Molecular Biophysics Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Precious Oyinloye
- Computational Chemistry and Molecular Biophysics Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
| | - Lei Shi
- Computational Chemistry and Molecular Biophysics Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
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Okorom AV, Camacho-Hernandez GA, Salomon K, Lee KH, Ku TC, Cao J, Won SJ, Friedman J, Lam J, Paule J, Rais R, Klein B, Xi ZX, Shi L, Loland CJ, Newman AH. Modifications to 1-(4-(2-Bis(4-fluorophenyl)methyl)sulfinyl)alkyl Alicyclic Amines That Improve Metabolic Stability and Retain an Atypical DAT Inhibitor Profile. J Med Chem 2024; 67:709-727. [PMID: 38117239 DOI: 10.1021/acs.jmedchem.3c02037] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Atypical dopamine transporter (DAT) inhibitors have shown therapeutic potential in the preclinical models of psychostimulant use disorders (PSUD). In rats, 1-(4-(2-((bis(4-fluorophenyl)methyl)sulfinyl)ethyl)-piperazin-1-yl)-propan-2-ol (JJC8-091, 3b) was effective in reducing the reinforcing effects of both cocaine and methamphetamine but did not exhibit psychostimulant behaviors itself. Improvements in DAT affinity and metabolic stability were desirable for discovering pipeline drug candidates. Thus, a series of 1-(4-(2-bis(4-fluorophenyl)methyl)sulfinyl)alkyl alicyclic amines were synthesized and evaluated for binding affinities at DAT and the serotonin transporter (SERT). Replacement of the piperazine with either a homopiperazine or a piperidine ring system was well tolerated at DAT (Ki range = 3-382 nM). However, only the piperidine analogues (20a-d) showed improved metabolic stability in rat liver microsomes as compared to the previously reported analogues. Compounds 12b and 20a appeared to retain an atypical DAT inhibitor profile, based on negligible locomotor activity in mice and molecular modeling that predicts binding to an inward-facing conformation of DAT.
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Affiliation(s)
- Amarachi V Okorom
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Gisela Andrea Camacho-Hernandez
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Kristine Salomon
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Kuo Hao Lee
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Therese C Ku
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Jianjing Cao
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Sung Joon Won
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Jacob Friedman
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
- Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Jenny Lam
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
- Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - James Paule
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
- Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Rana Rais
- Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, Maryland 21205, United States
| | - Benjamin Klein
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Zheng-Xiong Xi
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Lei Shi
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Claus J Loland
- Laboratory for Membrane Protein Dynamics, Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Amy Hauck Newman
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, Maryland 21224, United States
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Cruz B, Vozella V, Carper BA, Xu JC, Kirson D, Hirsch S, Nolen T, Bradley L, Fain K, Crawford M, Kosten TR, Zorrilla EP, Roberto M. FKBP5 inhibitors modulate alcohol drinking and trauma-related behaviors in a model of comorbid post-traumatic stress and alcohol use disorder. Neuropsychopharmacology 2023; 48:1144-1154. [PMID: 36396784 PMCID: PMC10267127 DOI: 10.1038/s41386-022-01497-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 11/19/2022]
Abstract
Post-traumatic stress disorder (PTSD) leads to enhanced alcohol drinking and development of alcohol use disorder (AUD). Identifying shared neural mechanisms might help discover new therapies for PTSD/AUD. Here, we employed a rat model of comorbid PTSD/AUD to evaluate compounds that inhibit FK506-binding protein 51 (FKBP5), a co-chaperone modulator of glucocorticoid receptors implicated in stress-related disorders. Male and female rats received a familiar avoidance-based shock stress followed by voluntary alcohol drinking. We then assessed trauma-related behaviors through sleep bout cycles, hyperarousal, fear overgeneralization, and irritability. To evaluate the role of stress and alcohol history on the sensitivity to FKBP5 inhibitors, in two separate studies, we administered two FKBP5 inhibitors, benztropine (Study 1) or SAFit2 (Study 2). FKBP5 inhibitors were administered on the last alcohol drinking session and prior to each trauma-related behavioral assessment. We also measured plasma corticosterone to assess the actions of FKBP5 inhibitors after familiar shock stress and alcohol drinking. Benztropine reduced alcohol preference in stressed males and females, while aggressive bouts were reduced in benztropine-treated stressed females. During hyperarousal, benztropine reduced several startle response outcomes across stressed males and females. Corticosterone was reduced in benztropine-treated stressed males. The selective FKBP5 inhibitor, SAFit2, reduced alcohol drinking in stressed males but not females, with no differences in irritability. Importantly, SAFit2 decreased fear overgeneralization in stressed males and females. SAFit2 also reduced corticosterone across stressed males and females. Neither FKBP5 inhibitor changed sleep bout structure. These findings indicate that FKBP5 inhibitors modulate stress-related alcohol drinking and partially modulate trauma-related behaviors. This work supports the hypothesis that targeting FKBP5 may alleviate PTSD/AUD comorbidity.
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Affiliation(s)
- Bryan Cruz
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92073, USA
| | - Valentina Vozella
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92073, USA
| | - Benjamin A Carper
- Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle Park, NC, 27709, USA
| | - Joy C Xu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92073, USA
| | - Dean Kirson
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92073, USA
- Department of Pharmacology, Addiction Science, and Toxicology, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Shawn Hirsch
- Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle Park, NC, 27709, USA
| | - Tracy Nolen
- Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle Park, NC, 27709, USA
| | - Lauren Bradley
- Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle Park, NC, 27709, USA
| | - Katie Fain
- Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle Park, NC, 27709, USA
| | - Meg Crawford
- Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle Park, NC, 27709, USA
| | - Thomas R Kosten
- Division of Alcohol and Addiction Psychiatry, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Eric P Zorrilla
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92073, USA.
| | - Marisa Roberto
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, 92073, USA.
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Zabegalov KN, Costa F, Viktorova YA, Maslov GO, Kolesnikova TO, Gerasimova EV, Grinevich VP, Budygin EA, Kalueff AV. Behavioral profile of adult zebrafish acutely exposed to a selective dopamine uptake inhibitor, GBR 12909. J Psychopharmacol 2023:2698811231166463. [PMID: 37125702 DOI: 10.1177/02698811231166463] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
BACKGROUND The dopamine transporter (DAT) is the main regulator of dopamine concentration in the extrasynaptic space. The pharmacological inhibition of the DAT results in a wide spectrum of behavioral manifestations, which have been identified so far in a limited number of species, mostly in rodents. AIM Here, we used another well-recognized model organism, the zebrafish (Danio rerio), to explore the behavioral effects of GBR 12909, a highly-affine selective DAT blocker. METHODS We evaluated zebrafish locomotion, novelty-related exploration, spatial cognition, and social phenotypes in the novel tank, habituation and shoaling tests, following acute 20-min water immersion in GBR 12909. RESULTS Our findings show hypolocomotion, anxiety-like state, and impaired spatial cognition in fish acutely treated with GBR 12909. This behavioral profile generally parallels that of the DAT knockout rodents and zebrafish, and it overlaps with behavioral effects of other DAT-inhibiting drugs of abuse, such as cocaine and D-amphetamine. CONCLUSION Collectively, our data support the utility of zebrafish in translational studies on DAT targeting neuropharmacology and strongly implicate DAT aberration as an important mechanisms involved in neurological and psychiatric diseases.
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Affiliation(s)
- Konstantin N Zabegalov
- Department of Neurobiology, Sirius University of Science and Technology, Sirius Federal Territory, Russia
| | - Fabiano Costa
- Department of Neurobiology, Sirius University of Science and Technology, Sirius Federal Territory, Russia
| | - Yuliya A Viktorova
- Department of Neurobiology, Sirius University of Science and Technology, Sirius Federal Territory, Russia
| | - Gleb O Maslov
- Department of Neurobiology, Sirius University of Science and Technology, Sirius Federal Territory, Russia
- Ural Federal University, Yekaterinburg, Sverdlovsk Region, Russia
| | - Tatiana O Kolesnikova
- Department of Neurobiology, Sirius University of Science and Technology, Sirius Federal Territory, Russia
| | - Elena V Gerasimova
- Department of Neurobiology, Sirius University of Science and Technology, Sirius Federal Territory, Russia
| | - Vladimir P Grinevich
- Department of Neurobiology, Sirius University of Science and Technology, Sirius Federal Territory, Russia
| | - Evgeny A Budygin
- Department of Neurobiology, Sirius University of Science and Technology, Sirius Federal Territory, Russia
| | - Allan V Kalueff
- Department of Neurobiology, Sirius University of Science and Technology, Sirius Federal Territory, Russia
- Ural Federal University, Yekaterinburg, Sverdlovsk Region, Russia
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7
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Shim KH, Kang MJ, Sharma N, An SSA. Beauty of the beast: anticholinergic tropane alkaloids in therapeutics. NATURAL PRODUCTS AND BIOPROSPECTING 2022; 12:33. [PMID: 36109439 PMCID: PMC9478010 DOI: 10.1007/s13659-022-00357-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/19/2022] [Indexed: 06/15/2023]
Abstract
Tropane alkaloids (TAs) are among the most valued chemical compounds known since pre-historic times. Poisonous plants from Solanaceae family (Hyoscyamus niger, Datura, Atropa belladonna, Scopolia lurida, Mandragora officinarum, Duboisia) and Erythroxylaceae (Erythroxylum coca) are rich sources of tropane alkaloids. These compounds possess the anticholinergic properties as they could block the neurotransmitter acetylcholine action in the central and peripheral nervous system by binding at either muscarinic and/or nicotinic receptors. Hence, they are of great clinical importance and are used as antiemetics, anesthetics, antispasmodics, bronchodilator and mydriatics. They also serve as the lead compounds to generate more effective drugs. Due to the important pharmacological action they are listed in the WHO list of essential medicines and are available in market with FDA approval. However, being anticholinergic in action, TA medication are under the suspicion of causing dementia and cognitive decline like other medications with anticholinergic action, interestingly which is incorrect. There are published reviews on chemistry, biosynthesis, pharmacology, safety concerns, biotechnological aspects of TAs but the detailed information on anticholinergic mechanism of action, clinical pharmacology, FDA approval and anticholinergic burden is lacking. Hence the present review tries to fill this lacuna by critically summarizing and discussing the above mentioned aspects.
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Affiliation(s)
- Kyu Hwan Shim
- Bionano Research Institute, Gachon University, 1342 Seongnam-daero, Sujeong-Gu, Seongnam, 461-701, South Korea
| | - Min Ju Kang
- Department of Neurology, Veterans Health Service Medical Center, Veterans Medical Research Institute, Seoul, South Korea
| | - Niti Sharma
- Bionano Research Institute, Gachon University, 1342 Seongnam-daero, Sujeong-Gu, Seongnam, 461-701, South Korea.
| | - Seong Soo A An
- Bionano Research Institute, Gachon University, 1342 Seongnam-daero, Sujeong-Gu, Seongnam, 461-701, South Korea.
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Wan F, Yu T, Hu J, Yin S, Li Y, Kou L, Chi X, Wu J, Sun Y, Zhou Q, Zou W, Zhang Z, Wang T. The pyrethroids metabolite 3-phenoxybenzoic acid induces dopaminergic degeneration. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156027. [PMID: 35605864 DOI: 10.1016/j.scitotenv.2022.156027] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 05/04/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
Exposure to pyrethroids, a significant class of the most widely used agricultural chemicals, has been associated with an increased risk of Parkinson's disease (PD). However, although many different pyrethroids induce roughly the same symptoms of Parkinsonism, the underlying mechanisms remain unknown. To find the shared key features among these mechanisms, we focused on 3-phenoxybenzoic acid (3-PBA), a common and prominent metabolite of most pyrethroids produced via hydrolysis by CEs in mammals. To determine the contribution of 3-PBA to the initiation and progression of PD, we performed in vivo and in vitro experiments, respectively, and found that 3-PBA not only accumulates in murine brain tissues over time but also further induces PD-like pathologies (increased α-syn and phospho-S129, decreased TH) to the same or even greater extent than the precursor pyrethroid. A before-after study of PET-DAT in the same mice revealed that low concentrations of 3-PBA (0.5 mg/kg) could paradoxically cause DAT to increase (22.46% higher than pre-drug test). The intervention of DAT inhibitors and activators respectively alleviated and enhanced the dopaminergic toxicity of 3-PBA, indicating that 3-PBA interacts with DAT. In particular, low concentrations of 3-PBA increase the DAT, which in turn induces 3-PBA to enter the dopaminergic neurons to exert toxic effects. Finally, we described a mechanism underlying this potential role of 3-PBA in the pathological aggregation of α-syn. Specifically, 3-PBA was found to dysregulate C/EBP β levels and further anomalously activate AEP in vivo and in vitro, accompanied by increased accumulation of pathologically cleaved α-syn (N103 fragments) and accelerated α-syn aggregation. All these results suggest that 3-PBA exposure could mimic the pathological and pathogenetic features of PD, showing that this metabolite is a key pathogenic compound in pyrethroid-related pathological effects and a possible dopamine neurotoxin. Additionally, our findings provide a crucial reference for the primary prevention of PD.
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Affiliation(s)
- Fang Wan
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ting Yu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Junjie Hu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sijia Yin
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yunna Li
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Liang Kou
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaosa Chi
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiawei Wu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yadi Sun
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qiulu Zhou
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wenkai Zou
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhentao Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, China.
| | - Tao Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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9
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Senior T, Botha MJ, Kennedy AR, Calvo-Castro J. Understanding the Contribution of Individual Amino Acid Residues in the Binding of Psychoactive Substances to Monoamine Transporters. ACS OMEGA 2020; 5:17223-17231. [PMID: 32715208 PMCID: PMC7376891 DOI: 10.1021/acsomega.0c01370] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 06/19/2020] [Indexed: 05/05/2023]
Abstract
The development of point-of-care detection methodologies for biologically relevant analytes that can facilitate rapid and appropriate treatment is at the forefront of current research efforts and interests. Among the various approaches, those exploiting host-guest chemistries where the optoelectronic signals of the chemical sensor can be modulated upon interaction with the target analyte are of particular interest. In aiding their rational development, judicious selection of peripheral functional groups anchored to core motifs with desired properties is critical. Herein, we report an in-depth investigation of the binding of three psychoactive substances, MDAI, mexedrone, and phenibut, to receptors of the monoamine transporters for dopamine, norepinephrine, and serotonin, particularly focusing on the role of individual amino acid residues. We first evaluated the conformational flexibility of the ligands by comparing their experimentally determined crystal structure geometries to those optimized by means of quantum as well as molecular mechanics, observing significant changes in the case of phenibut. Molecular docking studies were employed to identify preferential binding sites by means of calculated docking scores. In all cases, irrespective of the monoamine transporter, psychoactive substances exhibited preferred interaction with the S1 or central site of the proteins, in line with previous studies. However, we observed that experimental trends for their relative potency on the three transporters were only reproduced in the case of mexedrone. Subsequently, to further understand these findings and to pave the way for the rational development of superior chemical sensors for these substances, we computed the individual contributions of each nearest neighbor amino acid residue to the binding to the target analytes. Interestingly, these results are now in agreement with those experimental potency trends. In addition, these observations were in all cases associated with key intermolecular interactions with neighboring residues, such as tyrosine and aspartic acid, in the binding of the ligands to the monoamine transporter for dopamine. As a result, we believe this work will be of interest to those engaged in the rational development of chemical sensors for small molecule analytes as well as to those interested in the use of computational approaches to further understand protein-ligand interactions.
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Affiliation(s)
- Tamara Senior
- School
of Life and Medical Sciences, University
of Hertfordshire, Hatfield AL10 9AB, U.K.
| | - Michelle J. Botha
- School
of Life and Medical Sciences, University
of Hertfordshire, Hatfield AL10 9AB, U.K.
| | - Alan R. Kennedy
- Department
of Pure & Applied Chemistry, University
of Strathclyde, Glasgow G1 1XL, U.K.
| | - Jesus Calvo-Castro
- School
of Life and Medical Sciences, University
of Hertfordshire, Hatfield AL10 9AB, U.K.
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10
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Slack RD, Ku T, Cao J, Giancola J, Bonifazi A, Loland CJ, Gadiano A, Lam J, Rais R, Slusher BS, Coggiano M, Tanda G, Newman AH. Structure-Activity Relationships for a Series of (Bis(4-fluorophenyl)methyl)sulfinyl Alkyl Alicyclic Amines at the Dopamine Transporter: Functionalizing the Terminal Nitrogen Affects Affinity, Selectivity, and Metabolic Stability. J Med Chem 2020; 63:2343-2357. [PMID: 31661268 PMCID: PMC9617638 DOI: 10.1021/acs.jmedchem.9b01188] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Atypical dopamine transporter (DAT) inhibitors have shown therapeutic potential in preclinical models of psychostimulant abuse. In rats, 1-(4-(2-((bis(4-fluorophenyl)methyl)sulfinyl)ethyl)-piperazin-1-yl)-propan-2-ol (3b) was effective in reducing the reinforcing effects of both cocaine and methamphetamine but did not exhibit psychostimulant behaviors itself. While further development of 3b is ongoing, diastereomeric separation, as well as improvements in potency and pharmacokinetics were desirable for discovering pipeline drug candidates. Thus, a series of bis(4-fluorophenyl)methyl)sulfinyl)alkyl alicyclic amines, where the piperazine-2-propanol scaffold was modified, were designed, synthesized, and evaluated for binding affinities at DAT, as well as the serotonin transporter and σ1 receptors. Within the series, 14a showed improved DAT affinity (Ki = 23 nM) over 3b (Ki = 230 nM), moderate metabolic stability in human liver microsomes, and a hERG/DAT affinity ratio = 28. While 14a increased locomotor activity relative to vehicle, it was significantly lower than activity produced by cocaine. These results support further investigation of 14a as a potential treatment for psychostimulant use disorders.
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Affiliation(s)
- Rachel D. Slack
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, United States
| | - Therese Ku
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, United States
| | - Jianjing Cao
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, United States
| | - JoLynn Giancola
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, United States
| | - Alessandro Bonifazi
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, United States
| | - Claus J. Loland
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Alexandra Gadiano
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, United States
- Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, United States
| | - Jenny Lam
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, United States
- Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, United States
| | - Rana Rais
- Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, United States
| | - Barbara S. Slusher
- Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, United States
| | - Mark Coggiano
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, United States
| | - Gianluigi Tanda
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, United States
| | - Amy Hauck Newman
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse – Intramural Research Program, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, United States
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11
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Rotolo RA, Dragacevic V, Kalaba P, Urban E, Zehl M, Roller A, Wackerlig J, Langer T, Pistis M, De Luca MA, Caria F, Schwartz R, Presby RE, Yang JH, Samels S, Correa M, Lubec G, Salamone JD. The Novel Atypical Dopamine Uptake Inhibitor (S)-CE-123 Partially Reverses the Effort-Related Effects of the Dopamine Depleting Agent Tetrabenazine and Increases Progressive Ratio Responding. Front Pharmacol 2019; 10:682. [PMID: 31316379 PMCID: PMC6611521 DOI: 10.3389/fphar.2019.00682] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 05/27/2019] [Indexed: 12/21/2022] Open
Abstract
Animal studies of effort-based choice behavior are being used to model effort-related motivational dysfunctions in humans. With these procedures, animals are offered a choice between high-effort instrumental actions leading to highly valued reinforcers vs. low effort/low reward options. Several previous studies have shown that dopamine (DA) uptake inhibitors, including GBR12909, lisdexamfetamine, methylphenidate, and PRX-14040, can reverse the effort-related effects of the vesicular monoamine transport blocker tetrabenazine, which inhibits DA storage. Because many drugs that block DA transport act as major stimulants that also release DA, and produce a number of undesirable side effects, there is a need to develop and characterize novel atypical DA transport inhibitors. (S)-CE-123 ((S)-5-((benzhydrylsulfinyl) methyl)thiazole) is a recently developed analog of modafinil with the biochemical characteristics of an atypical DA transport blocker. The present paper describes the enantioselective synthesis and initial chemical characterization of (S)-CE-123, as well as behavioral experiments involving effort-based choice and microdialysis studies of extracellular DA. Rats were assessed using the fixed ratio 5/chow feeding choice test. Tetrabenazine (1.0 mg/kg) shifted choice behavior, decreasing lever pressing and increasing chow intake. (S)-CE-123 was coadministered at doses ranging from 6.0 to 24.0 mg/kg, and the highest dose partially but significantly reversed the effects of tetrabenazine, although this dose had no effect on fixed ratio responding when administered alone. Additional experiments showed that (S)-CE-123 significantly increased lever pressing on a progressive ratio/chow feeding choice task and that the effective dose (24.0 mg/kg) increased extracellular DA in nucleus accumbens core. In summary, (S)-CE-123 has the behavioral and neurochemical profile of a compound that can block DA transport, reverse the effort-related effects of tetrabenazine, and increase selection of high-effort progressive ratio responding. This suggests that (S)-CE-123 or a similar compound could be useful as a treatment for effort-related motivational dysfunction in humans.
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Affiliation(s)
- Renee A Rotolo
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States
| | - Vladimir Dragacevic
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Predrag Kalaba
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Ernst Urban
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Martin Zehl
- Department of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Alexander Roller
- X-ray Structure Analysis Centre, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Judith Wackerlig
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Thierry Langer
- Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria
| | - Marco Pistis
- Department of Biomedical Sciences, University of Cagliari, National Institute of Neuroscience (INN), Cagliari, Italy
| | - Maria Antonietta De Luca
- Department of Biomedical Sciences, University of Cagliari, National Institute of Neuroscience (INN), Cagliari, Italy
| | - Francesca Caria
- Department of Biomedical Sciences, University of Cagliari, National Institute of Neuroscience (INN), Cagliari, Italy
| | - Rebecca Schwartz
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States
| | - Rose E Presby
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States
| | - Jen-Hau Yang
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States
| | - Shanna Samels
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States
| | - Merce Correa
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States.,Àrea de Psicobiologia, Universitat Jaume I, Castelló, Spain
| | - Gert Lubec
- Department of Neuroproteomics, Paracelsus Medical University, Salzburg, Austria
| | - John D Salamone
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States
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12
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Solinas M, Belujon P, Fernagut PO, Jaber M, Thiriet N. Dopamine and addiction: what have we learned from 40 years of research. J Neural Transm (Vienna) 2018; 126:481-516. [PMID: 30569209 DOI: 10.1007/s00702-018-1957-2] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 11/17/2018] [Indexed: 12/22/2022]
Abstract
Among the neurotransmitters involved in addiction, dopamine (DA) is clearly the best known. The critical role of DA in addiction is supported by converging evidence that has been accumulated in the last 40 years. In the present review, first we describe the dopaminergic system in terms of connectivity, functioning and involvement in reward processes. Second, we describe the functional, structural, and molecular changes induced by drugs within the DA system in terms of neuronal activity, synaptic plasticity and transcriptional and molecular adaptations. Third, we describe how genetic mouse models have helped characterizing the role of DA in addiction. Fourth, we describe the involvement of the DA system in the vulnerability to addiction and the interesting case of addiction DA replacement therapy in Parkinson's disease. Finally, we describe how the DA system has been targeted to treat patients suffering from addiction and the result obtained in clinical settings and we discuss how these different lines of evidence have been instrumental in shaping our understanding of the physiopathology of drug addiction.
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Affiliation(s)
- Marcello Solinas
- Université de Poitiers, INSERM, U-1084, Laboratoire de Neurosciences Expérimentales et Cliniques, Poitiers, France.
| | - Pauline Belujon
- Université de Poitiers, INSERM, U-1084, Laboratoire de Neurosciences Expérimentales et Cliniques, Poitiers, France
| | - Pierre Olivier Fernagut
- Université de Poitiers, INSERM, U-1084, Laboratoire de Neurosciences Expérimentales et Cliniques, Poitiers, France
| | - Mohamed Jaber
- Université de Poitiers, INSERM, U-1084, Laboratoire de Neurosciences Expérimentales et Cliniques, Poitiers, France
- CHU de Poitiers, Poitiers, France
| | - Nathalie Thiriet
- Université de Poitiers, INSERM, U-1084, Laboratoire de Neurosciences Expérimentales et Cliniques, Poitiers, France
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13
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Moerke MJ, Ananthan S, Banks ML, Eltit JM, Freitas KC, Johnson AR, Saini SK, Steele TWE, Negus SS. Interactions between Cocaine and the Putative Allosteric Dopamine Transporter Ligand SRI-31142. J Pharmacol Exp Ther 2018; 367:222-233. [PMID: 30150482 PMCID: PMC6170971 DOI: 10.1124/jpet.118.250902] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/23/2018] [Indexed: 11/22/2022] Open
Abstract
Drugs that inhibit the dopamine (DA) transporter (DAT) include both therapeutic agents and abused drugs. Recent studies identified a novel series of putative allosteric DAT inhibitors, but the in vivo effects of these compounds are unknown. This study examined the abuse-related behavioral and neurochemical effects produced in rats by SRI-31142 [2-(7-methylimidazo[1,2-a]pyridin-6-yl)-N-(2-phenyl-2-(pyridin-4-yl)ethyl)quinazolin-4-amine], one compound from this series. In behavioral studies, intracranial self-stimulation (ICSS) was used to compare the effects produced by SRI-31142, the abused and nonselective DAT inhibitor cocaine, and the selective DAT inhibitor GBR-12935 [1-[2-(diphenylmethoxy)ethyl]-4-(3-phenylpropyl)piperazine]. In neurochemical studies, in vivo microdialysis was used to compare the effects of SRI-31142 and cocaine on levels of DA and serotonin in nucleus accumbens (NAc). The effects of SRI-31142 in combination with cocaine were also examined in both procedures. In contrast to cocaine and GBR-12935, SRI-31142 failed to produce abuse-related increases in ICSS or NAc DA; instead, SRI-31142 only decreased ICSS and NAc DA at a dose that was also sufficient to block cocaine-induced increases in ICSS and NAc DA. Pharmacokinetic studies suggested low but adequate brain penetration of SRI-31142, in vitro binding studies failed to identify likely non-DAT targets, and in vitro functional assays failed to confirm DA uptake inhibition in an assay of DAT-mediated fluorescent signals in live cells. These results indicate that SRI-31142 does not produce cocaine-like abuse-related effects in rats. SRI-31142 may have utility to block cocaine effects and may warrant further study as a candidate pharmacotherapy; however, the role of DAT in mediating these effects is unclear, and side effects may be a limiting factor.
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Affiliation(s)
- Megan J Moerke
- Departments of Pharmacology and Toxicology (M.J.M., M.L.B., K.C.F., A.R.J., S.S.N.) and Physiology and Biophysics (J.M.E., T.W.E.S.), Virginia Commonwealth University, Richmond, Virginia; and Chemistry Department, Drug Discovery Division, Southern Research, Birmingham, Alabama (S.A., S.K.S.)
| | - Subramaniam Ananthan
- Departments of Pharmacology and Toxicology (M.J.M., M.L.B., K.C.F., A.R.J., S.S.N.) and Physiology and Biophysics (J.M.E., T.W.E.S.), Virginia Commonwealth University, Richmond, Virginia; and Chemistry Department, Drug Discovery Division, Southern Research, Birmingham, Alabama (S.A., S.K.S.)
| | - Matthew L Banks
- Departments of Pharmacology and Toxicology (M.J.M., M.L.B., K.C.F., A.R.J., S.S.N.) and Physiology and Biophysics (J.M.E., T.W.E.S.), Virginia Commonwealth University, Richmond, Virginia; and Chemistry Department, Drug Discovery Division, Southern Research, Birmingham, Alabama (S.A., S.K.S.)
| | - Jose M Eltit
- Departments of Pharmacology and Toxicology (M.J.M., M.L.B., K.C.F., A.R.J., S.S.N.) and Physiology and Biophysics (J.M.E., T.W.E.S.), Virginia Commonwealth University, Richmond, Virginia; and Chemistry Department, Drug Discovery Division, Southern Research, Birmingham, Alabama (S.A., S.K.S.)
| | - Kelen C Freitas
- Departments of Pharmacology and Toxicology (M.J.M., M.L.B., K.C.F., A.R.J., S.S.N.) and Physiology and Biophysics (J.M.E., T.W.E.S.), Virginia Commonwealth University, Richmond, Virginia; and Chemistry Department, Drug Discovery Division, Southern Research, Birmingham, Alabama (S.A., S.K.S.)
| | - Amy R Johnson
- Departments of Pharmacology and Toxicology (M.J.M., M.L.B., K.C.F., A.R.J., S.S.N.) and Physiology and Biophysics (J.M.E., T.W.E.S.), Virginia Commonwealth University, Richmond, Virginia; and Chemistry Department, Drug Discovery Division, Southern Research, Birmingham, Alabama (S.A., S.K.S.)
| | - Surendra K Saini
- Departments of Pharmacology and Toxicology (M.J.M., M.L.B., K.C.F., A.R.J., S.S.N.) and Physiology and Biophysics (J.M.E., T.W.E.S.), Virginia Commonwealth University, Richmond, Virginia; and Chemistry Department, Drug Discovery Division, Southern Research, Birmingham, Alabama (S.A., S.K.S.)
| | - Tyler W E Steele
- Departments of Pharmacology and Toxicology (M.J.M., M.L.B., K.C.F., A.R.J., S.S.N.) and Physiology and Biophysics (J.M.E., T.W.E.S.), Virginia Commonwealth University, Richmond, Virginia; and Chemistry Department, Drug Discovery Division, Southern Research, Birmingham, Alabama (S.A., S.K.S.)
| | - S Stevens Negus
- Departments of Pharmacology and Toxicology (M.J.M., M.L.B., K.C.F., A.R.J., S.S.N.) and Physiology and Biophysics (J.M.E., T.W.E.S.), Virginia Commonwealth University, Richmond, Virginia; and Chemistry Department, Drug Discovery Division, Southern Research, Birmingham, Alabama (S.A., S.K.S.)
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14
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Collins GT, France CP. Effects of lorcaserin and buspirone, administered alone and as a mixture, on cocaine self-administration in male and female rhesus monkeys. Exp Clin Psychopharmacol 2018; 26:488-496. [PMID: 29952618 PMCID: PMC6162158 DOI: 10.1037/pha0000209] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cocaine use disorder is a serious public health issue for which there is no effective pharmacotherapy. One strategy to speed development of medications for cocaine use disorder is to repurpose drugs already approved for use in humans based on their ability to interact with targets known to be important for addiction. Two such drugs, lorcaserin (Belviq; a drug with serotonin [5-HT]2C receptor agonist properties) and buspirone (Buspar; a drug with 5-HT1A receptor partial agonist and dopamine D3/D4 receptor antagonist properties) can produce modest decreases in cocaine self-administration in rhesus monkeys. The current study evaluated the effectiveness of mixtures of lorcaserin and buspirone (at fixed dose ratios of 3:1, 1:1, and 1:3 relative to each drug's ID50) to reduce responding for 0.032 mg/kg/inf cocaine under a progressive ratio schedule of reinforcement in 2 male and 2 female rhesus monkeys. Dose addition analyses were used to determine if the effects of the drug mixtures differed from those predicted for an additive interaction between lorcaserin and buspirone. Dose-dependent reductions of cocaine self-administration were observed when lorcaserin and buspirone were administered alone, as well as when they were administered as 3:1, 1:1, and 1:3 fixed ratio mixtures of lorcaserin + buspirone. The effects of the 1:1 mixture of lorcaserin + buspirone on cocaine self-administration were supraadditive, whereas the effects of 3:1 and 1:3 mixtures were additive. Together, these results indicate that a combination therapy containing a mixture of lorcaserin and buspirone might be more effective than either drug alone at treating cocaine use disorder. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
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Affiliation(s)
- Gregory T. Collins
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX, 78229, USA,Addiction Research, Treatment & Training Center of Excellence, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX, 78229, USA,South Texas Veterans Health Care System, 7400 Merton Minter Dr., San Antonio, TX, 78229, USA
| | - Charles P. France
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX, 78229, USA,Addiction Research, Treatment & Training Center of Excellence, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX, 78229, USA
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15
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Tomlinson MJ, Krout D, Pramod AB, Lever JR, Newman AH, Henry LK, Vaughan RA. Identification of the benztropine analog [ 125I]GA II 34 binding site on the human dopamine transporter. Neurochem Int 2018; 123:34-45. [PMID: 30125594 DOI: 10.1016/j.neuint.2018.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/10/2018] [Accepted: 08/14/2018] [Indexed: 12/21/2022]
Abstract
The dopamine transporter (DAT) is a neuronal membrane protein that is responsible for reuptake of dopamine (DA) from the synapse and functions as a major determinant in control of DA neurotransmission. Cocaine and many psychostimulant drugs bind to DAT and block reuptake, inducing DA overflow that forms the neurochemical basis for euphoria and addiction. Paradoxically, however, some ligands such as benztropine (BZT) bind to DAT and inhibit reuptake but do not produce these effects, and it has been hypothesized that differential mechanisms of binding may stabilize specific transporter conformations that affect downstream neurochemical or behavioral outcomes. To investigate the binding mechanisms of BZT on DAT we used the photoaffinity BZT analog [125I]N-[n-butyl-4-(4‴-azido-3‴-iodophenyl)]-4',4″-difluoro-3α-(diphenylmethoxy)tropane ([125I]GA II 34) to identify the site of cross-linking and predict the binding pose relative to that of previously-examined cocaine photoaffinity analogs. Biochemical findings show that adduction of [125I]GA II 34 occurs at residues Asp79 or Leu80 in TM1, with molecular modeling supporting adduction to Leu80 and a pharmacophore pose in the central S1 site similar to that of cocaine and cocaine analogs. Substituted cysteine accessibility method protection analyses verified these findings, but identified some differences in structural stabilization relative to cocaine that may relate to BZT neurochemical outcomes.
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Affiliation(s)
- Michael J Tomlinson
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, United States
| | - Danielle Krout
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, United States
| | - Akula Bala Pramod
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, United States
| | - John R Lever
- Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, United States; Department of Radiology and Radiopharmaceutical Sciences Institute, University of Missouri, Columbia, MO 65211, United States
| | - Amy Hauck Newman
- Medicinal Chemistry Section, National Institute on Drug Abuse - Intramural Research Program, Baltimore, MD 21224, United States
| | - L Keith Henry
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, United States.
| | - Roxanne A Vaughan
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, United States.
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16
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Dassanayake AF, Canales JJ. Replacement treatment during extinction training with the atypical dopamine uptake inhibitor, JHW-007, reduces relapse to methamphetamine seeking. Neurosci Lett 2018; 671:88-92. [PMID: 29452175 DOI: 10.1016/j.neulet.2018.02.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/26/2018] [Accepted: 02/12/2018] [Indexed: 12/29/2022]
Abstract
There are currently no approved medications to effectively counteract the effects of methamphetamine (METH), reduce its abuse and prolong abstinence from it. Data accumulated in recent years have shown that a range of N-substituted benztropine (BZT) analogues possesses psychopharmacological features consistent with those of a potential replacement or "substitute" treatment for stimulant addiction. On the other hand, the evidence that antidepressant therapy may effectively prevent relapse to stimulant seeking is controversial. Here, we compared in rats the ability of the BZT analogue and high affinity dopamine (DA) reuptake inhibitor, JHW-007, and the antidepressant, trazodone, administered during extinction sessions after chronic METH self-administration, to alter METH-primed reinstatement of drug seeking. The data showed that trazodone produced paradoxical effects on lever pressing during extinction of METH self-administration, decreasing active, but increasing inactive, lever pressing. JHW-007 did not have any observable effects on extinction training. Importantly, JHW-007 significantly attenuated METH-primed reinstatement, whereas trazodone enhanced it. These findings lend support to the candidacy of selective DA uptake blockers, such as JHW-007, as potential treatments for METH addiction, but not to the use of antidepressant medication as a single therapeutic approach for relapse prevention.
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Affiliation(s)
- Ashlea F Dassanayake
- Division of Psychology, School of Medicine, University of Tasmania, Private Bag 30, Hobart, TAS, 7001, Australia
| | - Juan J Canales
- Division of Psychology, School of Medicine, University of Tasmania, Private Bag 30, Hobart, TAS, 7001, Australia.
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17
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Collins GT, Gerak LR, France CP. The behavioral pharmacology and therapeutic potential of lorcaserin for substance use disorders. Neuropharmacology 2017; 142:63-71. [PMID: 29246856 DOI: 10.1016/j.neuropharm.2017.12.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 11/28/2017] [Accepted: 12/11/2017] [Indexed: 10/18/2022]
Abstract
Substance abuse is serious public health problem for which there are few effective pharmacotherapies. Traditional strategies for drug development have focused on antagonists to block the abuse-related effects of a drug at its site of action, and agonists to replace/mimic the effects of the abused substance. However, recent efforts have targeted receptors, such as serotonin (5-HT)2 receptors, that can indirectly modulate dopamine neurotransmission with the goal of developing a pharmacotherapy that might be effective at reducing the abuse-related effects of drugs more generally. Lorcaserin is a 5-HT2C receptor-preferring agonist that is approved by the US Food and Drug Administration for the treatment of obesity. Mounting evidence from preclinical and clinical studies suggests that lorcaserin might also be effective at reducing the abuse-related effects of drugs with different pharmacological mechanisms (e.g., cocaine, heroin, ethanol, and nicotine). Lorcaserin represents a promising and important first step towards the development a new class of pharmacotherapies that have the potential to dramatically improve the treatment of substance abuse. This article will review the behavioral pharmacology of 5-HT2C receptor-preferring agonists, with a focus on lorcaserin, and evaluate the preclinical evidence supporting the development of lorcaserin for treating substance abuse. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'.
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Affiliation(s)
- Gregory T Collins
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; South Texas Veterans Health Care System, San Antonio, TX 78229, USA; Addiction Research, Treatment & Training Center of Excellence, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Lisa R Gerak
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Addiction Research, Treatment & Training Center of Excellence, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Charles P France
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Addiction Research, Treatment & Training Center of Excellence, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
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18
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Krout D, Pramod AB, Dahal RA, Tomlinson MJ, Sharma B, Foster JD, Zou MF, Boatang C, Newman AH, Lever JR, Vaughan RA, Henry LK. Inhibitor mechanisms in the S1 binding site of the dopamine transporter defined by multi-site molecular tethering of photoactive cocaine analogs. Biochem Pharmacol 2017; 142:204-215. [PMID: 28734777 DOI: 10.1016/j.bcp.2017.07.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 07/17/2017] [Indexed: 10/19/2022]
Abstract
Dopamine transporter (DAT) blockers like cocaine and many other abused and therapeutic drugs bind and stabilize an inactive form of the transporter inhibiting reuptake of extracellular dopamine (DA). The resulting increases in DA lead to the ability of these drugs to induce psychomotor alterations and addiction, but paradoxical findings in animal models indicate that not all DAT antagonists induce cocaine-like behavioral outcomes. How this occurs is not known, but one possibility is that uptake inhibitors may bind at multiple locations or in different poses to stabilize distinct conformational transporter states associated with differential neurochemical endpoints. Understanding the molecular mechanisms governing the pharmacological inhibition of DAT is therefore key for understanding the requisite interactions for behavioral modulation and addiction. Previously, we leveraged complementary computational docking, mutagenesis, peptide mapping, and substituted cysteine accessibility strategies to identify the specific adduction site and binding pose for the crosslinkable, photoactive cocaine analog, RTI 82, which contains a photoactive azide attached at the 2β position of the tropane pharmacophore. Here, we utilize similar methodology with a different cocaine analog N-[4-(4-azido-3-I-iodophenyl)-butyl]-2-carbomethoxy-3-(4-chlorophenyl)tropane, MFZ 2-24, where the photoactive azide is attached to the tropane nitrogen. In contrast to RTI 82, which crosslinked into residue Phe319 of transmembrane domain (TM) 6, our findings show that MFZ 2-24 adducts to Leu80 in TM1 with modeling and biochemical data indicating that MFZ 2-24, like RTI 82, occupies the central S1 binding pocket with the (+)-charged tropane ring nitrogen coordinating with the (-)-charged carboxyl side chain of Asp79. The superimposition of the tropane ring in the three-dimensional binding poses of these two distinct ligands provides strong experimental evidence for cocaine binding to DAT in the S1 site and the importance of the tropane moiety in competitive mechanisms of DA uptake inhibition. These findings set a structure-function baseline for comparison of typical and atypical DAT inhibitors and how their interactions with DAT could lead to the loss of cocaine-like behaviors.
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Affiliation(s)
- Danielle Krout
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, USA
| | - Akula Bala Pramod
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, USA
| | - Rejwi Acharya Dahal
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, USA
| | - Michael J Tomlinson
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, USA
| | - Babita Sharma
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, USA
| | - James D Foster
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, USA
| | - Mu-Fa Zou
- Medicinal Chemistry Section, National Institute on Drug Abuse - Intramural Research Program, Baltimore, MD 21224, USA
| | - Comfort Boatang
- Medicinal Chemistry Section, National Institute on Drug Abuse - Intramural Research Program, Baltimore, MD 21224, USA
| | - Amy Hauck Newman
- Medicinal Chemistry Section, National Institute on Drug Abuse - Intramural Research Program, Baltimore, MD 21224, USA
| | - John R Lever
- Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; Department of Radiology and Radiopharmaceutical Sciences Institute, University of Missouri, Columbia, MO 65211, USA
| | - Roxanne A Vaughan
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, USA.
| | - L Keith Henry
- Department of Biomedical Sciences, University of North Dakota School of Medicine and Health Sciences, 1301 North Columbia Road, Grand Forks, ND 58202, USA.
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19
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The Novel Modafinil Analog, JJC8-016, as a Potential Cocaine Abuse Pharmacotherapeutic. Neuropsychopharmacology 2017; 42:1871-1883. [PMID: 28266501 PMCID: PMC5564383 DOI: 10.1038/npp.2017.41] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 02/15/2017] [Accepted: 02/20/2017] [Indexed: 12/22/2022]
Abstract
(±)Modafinil ((±)MOD) and its R-enantiomer (R-modafinil; R-MOD) have been investigated for their potential as treatments for psychostimulant addiction. We recently reported a series of (±)MOD analogs, of which JJC8-016 (N-(2-((bis(4-fluorophenyl)methyl)thio)ethyl)-3-phenylpropan-1-amine) was selected for further development. JJC8-016 and R-MOD were evaluated for binding across ~70 receptors, transporters, and enzymes. Although at a concentration of 10 μM, there were many hits for JJC8-016, binding affinities in the range of its DAT affinity were only observed at the serotonin transporter (SERT), dopamine D2-like, and sigma1 receptors. R-MOD was more selective, but had much lower affinity at the DAT (Ki=3 μM) than JJC8-016 (Ki=116 nM). In rats, systemic administration of R-MOD alone (10-30 mg/kg i.p.) dose-dependently increased locomotor activity and electrical brain-stimulation reward, whereas JJC8-016 (10-30 mg/kg i.p.) did not produce these effects. Strikingly, pretreatment with JJC8-016 dose-dependently inhibited cocaine-enhanced locomotion, cocaine self-administration, and cocaine-induced reinstatement of drug-seeking behavior, whereas R-MOD inhibited cocaine-induced reinstatement only at the high dose of 100 mg/kg. Notably, JJC8-016 alone neither altered extracellular dopamine in the nucleus accumbens nor maintained self-administration. It also failed to induce reinstatement of drug-seeking behavior. These findings suggest that JJC8-016 is a unique DAT inhibitor that has no cocaine-like abuse potential by itself. Moreover, pretreatment with JJC8-016 significantly inhibits cocaine-taking and cocaine-seeking behavior likely by interfering with cocaine binding to DAT. In addition, off-target actions may also contribute to its potential therapeutic utility in the treatment of cocaine abuse.
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20
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Xi ZX, Song R, Li X, Lu GY, Peng XQ, He Y, Bi GH, Sheng SP, Yang HJ, Zhang H, Li J, Froimowitz M, Gardner EL. CTDP-32476: A Promising Agonist Therapy for Treatment of Cocaine Addiction. Neuropsychopharmacology 2017; 42:682-694. [PMID: 27534265 PMCID: PMC5240176 DOI: 10.1038/npp.2016.155] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 07/19/2016] [Accepted: 07/31/2016] [Indexed: 11/09/2022]
Abstract
Agonist-replacement therapies have been successfully used for treatment of opiate and nicotine addiction, but not for cocaine addiction. One of the major obstacles is the cocaine-like addictive potential of the agonists themselves. We report here an atypical dopamine (DA) transporter (DAT) inhibitor, CTDP-32476, that may have translational potential for treating cocaine addiction. In vitro ligand-binding assays suggest that CTDP-32476 is a potent and selective DAT inhibitor and a competitive inhibitor of cocaine binding to the DAT. Systemic administration of CTDP-32476 alone produced a slow-onset, long-lasting increase in extracellular nucleus accumbens DA, locomotion, and brain-stimulation reward. Drug-naive rats did not self-administer CTDP-32476. In a substitution test, cocaine self-administration rats displayed a progressive reduction in CTDP-32476 self-administration with an extinction pattern of drug-taking behavior, suggesting significantly lower addictive potential than cocaine. Pretreatment with CTDP-32476 inhibited cocaine self-administration, cocaine-associated cue-induced relapse to drug seeking, and cocaine-enhanced extracellular DA in the nucleus accumbens. These findings suggest that CTDP-32476 is a unique DAT inhibitor that not only could satisfy 'drug hunger' through its slow-onset long-lasting DAT inhibitor action, but also render subsequent administration of cocaine ineffectual-thus constituting a novel and unique compound with translational potential as an agonist therapy for treatment of cocaine addiction.
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Affiliation(s)
- Zheng-Xiong Xi
- Neuropsychopharmacology Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA
| | - Rui Song
- State Key Laboratory of Toxicology and Medical Countermeasures and Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Xia Li
- Department of Psychiatry, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Guan-Yi Lu
- State Key Laboratory of Toxicology and Medical Countermeasures and Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Xiao-Qing Peng
- Department of Behavioral Health, Saint Elizabeth's Hospital, Washington, DC, USA
| | - Yi He
- Neuropsychopharmacology Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA
| | - Guo-Hua Bi
- Neuropsychopharmacology Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA
| | - Siyuan Peter Sheng
- Neuropsychopharmacology Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA
| | - Hong-Ju Yang
- Neuropsychopharmacology Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA
| | - Haiying Zhang
- Neuropsychopharmacology Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA
| | - Jin Li
- State Key Laboratory of Toxicology and Medical Countermeasures and Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Mark Froimowitz
- Massachusetts College of Pharmacy and Health Sciences, Boston, MA, USA
| | - Eliot L Gardner
- Neuropsychopharmacology Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, USA
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21
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Cao J, Slack RD, Bakare OM, Burzynski C, Rais R, Slusher BS, Kopajtic T, Bonifazi A, Ellenberger MP, Yano H, He Y, Bi GH, Xi ZX, Loland CJ, Newman AH. Novel and High Affinity 2-[(Diphenylmethyl)sulfinyl]acetamide (Modafinil) Analogues as Atypical Dopamine Transporter Inhibitors. J Med Chem 2016; 59:10676-10691. [PMID: 27933960 DOI: 10.1021/acs.jmedchem.6b01373] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The development of pharmacotherapeutic treatments of psychostimulant abuse has remained a challenge, despite significant efforts made toward relevant mechanistic targets, such as the dopamine transporter (DAT). The atypical DAT inhibitors have received attention due to their promising pharmacological profiles in animal models of cocaine and methamphetamine abuse. Herein, we report a series of modafinil analogues that have an atypical DAT inhibitor profile. We extended SAR by chemically manipulating the oxidation states of the sulfoxide and the amide functional groups, halogenating the phenyl rings, and/or functionalizing the terminal nitrogen with substituted piperazines, resulting in several novel leads such as 11b, which demonstrated high DAT affinity (Ki = 2.5 nM) and selectivity without producing concomitant locomotor stimulation in mice, as compared to cocaine. These results are consistent with an atypical DAT inhibitor profile and suggest that 11b may be a potential lead for development as a psychostimulant abuse medication.
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Affiliation(s)
- Jianjing Cao
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Rachel D Slack
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Oluyomi M Bakare
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Caitlin Burzynski
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States.,Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine , 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Rana Rais
- Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine , 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Barbara S Slusher
- Department of Neurology, Johns Hopkins Drug Discovery, The Johns Hopkins University School of Medicine , 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Theresa Kopajtic
- Psychobiology Section, Molecular Neuropsychiatry Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 251 Bayview Boulevard, Baltimore, Maryland 21224, United States
| | - Alessandro Bonifazi
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Michael P Ellenberger
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Hideaki Yano
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Yi He
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Guo-Hua Bi
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Zheng-Xiong Xi
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States
| | - Claus J Loland
- Molecular Neuropharmacology and Genetics Laboratory, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen , DK-2200 Copenhagen, Denmark
| | - Amy Hauck Newman
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health , 333 Cassell Drive, Baltimore, Maryland 21224, United States
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22
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Brown DP, Rogers DT, Gunjan SK, Gerhardt GA, Littleton JM. Target-directed discovery and production of pharmaceuticals in transgenic mutant plant cells. J Biotechnol 2016; 238:9-14. [PMID: 27637316 PMCID: PMC5242497 DOI: 10.1016/j.jbiotec.2016.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 08/31/2016] [Accepted: 09/12/2016] [Indexed: 01/09/2023]
Abstract
Plants are a source of complex bioactive compounds, with value as pharmaceuticals, or leads for synthetic modification. Many of these secondary metabolites have evolved as defenses against competing organisms and their pharmaceutical value is "accidental", resulting from homology between target proteins in these competitors, and human molecular therapeutic targets. Here we show that it is possible to use mutation and selection of plant cells to re-direct their "evolution" toward metabolites that interact with the therapeutic target proteins themselves. This is achieved by expressing the human target protein in plant cells, and selecting mutants for survival based on the interaction of their metabolome with this target. This report describes the successful evolution of hairy root cultures of a Lobelia species toward increased biosynthesis of metabolites that inhibit the human dopamine transporter protein. Many of the resulting selected mutants are overproducing the active metabolite found in the wild-type plant, but others overproduce active metabolites that are not readily detectable in non-mutants. This technology can access the whole genomic capability of a plant species to biosynthesize metabolites with a specific target. It has potential value as a novel platform for plant drug discovery and production, or as a means of optimizing the therapeutic value of medicinal plant extracts.
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Key Words
- 1,2,3,6-tetrahydropyridine (MPTP)
- 1,2,3,6-tetrahydropyridine (MPTP: Pubmed CID: 1388)
- 1-methy-4-phenylpyridinium (MPP+: Pubmed CID: 39484)
- Activation tagging mutagenesis (ATM)
- Hairy root cultures
- Human dopamine transporter protein (hDAT)
- Lobelia cardinalis
- Lobinaline (1-Methyl-5,7-diphenyl-6-(3,4,5,6-tetrahydro-2-pyridinyl)decahydroquinoline (Pubmed CID: 419029)
- [(3)H]GBR12935 (Pubmed CID: 3455)
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Affiliation(s)
- D P Brown
- Department of Anatomy & Neurobiology, University of Kentucky, Lexington, KY, 40536-0298, USA
| | - D T Rogers
- Naprogenix Inc, University of Kentucky, AsTeCC, Lexington, KY 40506-0286, USA.
| | - S K Gunjan
- Department of Psychology, University of Kentucky, Lexington, KY, 40506-0044, USA
| | - G A Gerhardt
- Department of Anatomy & Neurobiology, University of Kentucky, Lexington, KY, 40536-0298, USA
| | - J M Littleton
- Naprogenix Inc, University of Kentucky, AsTeCC, Lexington, KY 40506-0286, USA; Department of Psychology, University of Kentucky, Lexington, KY, 40506-0044, USA
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23
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Jia X, Wang F, Han Y, Geng X, Li M, Shi Y, Lu L, Chen Y. miR-137 and miR-491 Negatively Regulate Dopamine Transporter Expression and Function in Neural Cells. Neurosci Bull 2016; 32:512-522. [PMID: 27628529 DOI: 10.1007/s12264-016-0061-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 07/13/2016] [Indexed: 12/14/2022] Open
Abstract
The dopamine transporter (DAT) is involved in the regulation of extracellular dopamine levels. A 40-bp variable-number tandem repeat (VNTR) polymorphism in the 3'-untranslated region (3'UTR) of the DAT has been reported to be associated with various phenotypes that are involved in the aberrant regulation of dopaminergic neurotransmission. In the present study, we found that miR-137 and miR-491 caused a marked reduction of DAT expression, thereby influencing neuronal dopamine transport. Moreover, the regulation of miR-137 and miR-491 on this transport disappeared after the DAT was silenced. The miR-491 seed region that is located on the VNTR sequence in the 3'UTR of the DAT and the regulatory effect of miR-491 on the DAT depended on the VNTR copy-number. These data indicate that miR-137 and miR-491 regulate DAT expression and dopamine transport at the post-transcriptional level, suggesting that microRNA may be targeted for the treatment of diseases associated with DAT dysfunction.
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Affiliation(s)
- Xiaojian Jia
- Shenzhen Key Laboratory for Drug Addiction and Medication Safety, Department of Ultrasound, Peking University Shenzhen Hospital, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, 518036, China
| | - Feng Wang
- Shenzhen Key Laboratory for Drug Addiction and Medication Safety, Department of Ultrasound, Peking University Shenzhen Hospital, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, 518036, China.,Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, 453000, China
| | - Ying Han
- Institute of Mental Health, Peking University Sixth Hospital and Key Laboratory of Mental Health, National Institute on Drug Dependence, Peking University, Beijing, 100191, China
| | - Xuewen Geng
- Shenzhen Key Laboratory for Drug Addiction and Medication Safety, Department of Ultrasound, Peking University Shenzhen Hospital, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, 518036, China
| | - Minghua Li
- Shenzhen Key Laboratory for Drug Addiction and Medication Safety, Department of Ultrasound, Peking University Shenzhen Hospital, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, 518036, China
| | - Yu Shi
- Shenzhen Key Laboratory for Drug Addiction and Medication Safety, Department of Ultrasound, Peking University Shenzhen Hospital, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, 518036, China
| | - Lin Lu
- Institute of Mental Health, Peking University Sixth Hospital and Key Laboratory of Mental Health, National Institute on Drug Dependence, Peking University, Beijing, 100191, China.
| | - Yun Chen
- Shenzhen Key Laboratory for Drug Addiction and Medication Safety, Department of Ultrasound, Peking University Shenzhen Hospital, Biomedical Research Institute, Shenzhen Peking University - The Hong Kong University of Science and Technology Medical Center, Shenzhen, 518036, China.
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24
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Brown DP, Rogers DT, Pomerleau F, Siripurapu KB, Kulshrestha M, Gerhardt GA, Littleton JM. Novel multifunctional pharmacology of lobinaline, the major alkaloid from Lobelia cardinalis. Fitoterapia 2016; 111:109-23. [PMID: 27105955 PMCID: PMC5299595 DOI: 10.1016/j.fitote.2016.04.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/15/2016] [Accepted: 04/17/2016] [Indexed: 01/18/2023]
Abstract
In screening a library of plant extracts from ~1000 species native to the Southeastern United States, Lobelia cardinalis was identified as containing nicotinic acetylcholine receptor (nicAchR) binding activity which was relatively non-selective for the α4β2- and α7-nicAchR subtypes. This nicAchR binding profile is atypical for plant-derived nicAchR ligands, the majority of which are highly selective for α4β2-nicAchRs. Its potential therapeutic relevance is noteworthy since agonism of α4β2- and α7-nicAchRs is associated with anti-inflammatory and neuroprotective properties. Bioassay-guided fractionation of L. cardinalis extracts led to the identification of lobinaline, a complex binitrogenous alkaloid, as the main source of the unique nicAchR binding profile. Purified lobinaline was a potent free radical scavenger, displayed similar binding affinity at α4β2- and α7-nicAchRs, exhibited agonist activity at nicAchRs in SH-SY5Y cells, and inhibited [(3)H]-dopamine (DA) uptake in rat striatal synaptosomes. Lobinaline significantly increased fractional [(3)H] release from superfused rat striatal slices preloaded with [(3)H]-DA, an effect that was inhibited by the non-selective nicAchR antagonist mecamylamine. In vivo electrochemical studies in urethane-anesthetized rats demonstrated that lobinaline locally applied in the striatum significantly prolonged clearance of exogenous DA by the dopamine transporter (DAT). In contrast, lobeline, the most thoroughly investigated Lobelia alkaloid, is an α4β2-nicAchR antagonist, a poor free radical scavenger, and is a less potent DAT inhibitor. These previously unreported multifunctional effects of lobinaline make it of interest as a lead to develop therapeutics for neuropathological disorders that involve free radical generation, cholinergic, and dopaminergic neurotransmission. These include neurodegenerative conditions, such as Parkinson's disease, and drug abuse.
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Affiliation(s)
- Dustin P Brown
- College of Medicine, Department of Anatomy & Neurobiology, University of Kentucky Chandler Medical Center, 138 Leader Avenue, Lexington, KY 40536-9983, USA
| | - Dennis T Rogers
- Naprogenix™, UK-AsTeCC, 145 Graham Avenue, Lexington, KY 40506-0286, USA.
| | - Francois Pomerleau
- College of Medicine, Department of Anatomy & Neurobiology, University of Kentucky Chandler Medical Center, 138 Leader Avenue, Lexington, KY 40536-9983, USA; College of Medicine, Parkinson's Disease Translational Research Center for Excellence, University of Kentucky Chandler Medical Center, 138 Leader Avenue, Lexington, KY 40536-9983, USA; College of Medicine, Center for Microelectrode Technology, University of Kentucky Chandler Medical Center, 138 Leader Avenue, Lexington, KY 40536-9983, USA
| | - Kirin B Siripurapu
- College of Arts and Sciences, Department of Psychology, University of Kentucky, Kastle Hall, Lexington, KY 40506-0044, USA
| | - Manish Kulshrestha
- College of Agriculture, Department of Biosystems & Agricultural Engineering, University of Kentucky, 1100 S. Limestone, Lexington, KY 40546-0091, USA
| | - Greg A Gerhardt
- College of Medicine, Department of Anatomy & Neurobiology, University of Kentucky Chandler Medical Center, 138 Leader Avenue, Lexington, KY 40536-9983, USA; College of Medicine, Department of Neurology, University of Kentucky Chandler Medical Center, 138 Leader Avenue, Lexington, KY 40536-9983, USA; College of Medicine, Department of Psychiatry, University of Kentucky Chandler Medical Center, 138 Leader Avenue, Lexington, KY 40536-9983, USA; College of Medicine, Department of Neurosurgery, University of Kentucky Chandler Medical Center, 138 Leader Avenue, Lexington, KY 40536-9983, USA; College of Medicine, Parkinson's Disease Translational Research Center for Excellence, University of Kentucky Chandler Medical Center, 138 Leader Avenue, Lexington, KY 40536-9983, USA; College of Medicine, Center for Microelectrode Technology, University of Kentucky Chandler Medical Center, 138 Leader Avenue, Lexington, KY 40536-9983, USA
| | - John M Littleton
- Naprogenix™, UK-AsTeCC, 145 Graham Avenue, Lexington, KY 40506-0286, USA; College of Arts and Sciences, Department of Psychology, University of Kentucky, Kastle Hall, Lexington, KY 40506-0044, USA
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25
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Pei Y, Asif-Malik A, Canales JJ. Trace Amines and the Trace Amine-Associated Receptor 1: Pharmacology, Neurochemistry, and Clinical Implications. Front Neurosci 2016; 10:148. [PMID: 27092049 PMCID: PMC4820462 DOI: 10.3389/fnins.2016.00148] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 03/21/2016] [Indexed: 01/30/2023] Open
Abstract
Biogenic amines are a collection of endogenous molecules that play pivotal roles as neurotransmitters and hormones. In addition to the "classical" biogenic amines resulting from decarboxylation of aromatic acids, including dopamine (DA), norepinephrine, epinephrine, serotonin (5-HT), and histamine, other biogenic amines, present at much lower concentrations in the central nervous system (CNS), and hence referred to as "trace" amines (TAs), are now recognized to play significant neurophysiological and behavioral functions. At the turn of the century, the discovery of the trace amine-associated receptor 1 (TAAR1), a phylogenetically conserved G protein-coupled receptor that is responsive to both TAs, such as β-phenylethylamine, octopamine, and tyramine, and structurally-related amphetamines, unveiled mechanisms of action for TAs other than interference with aminergic pathways, laying the foundations for deciphering the functional significance of TAs and its mammalian CNS receptor, TAAR1. Although, its molecular interactions and downstream targets have not been fully elucidated, TAAR1 activation triggers accumulation of intracellular cAMP, modulates PKA and PKC signaling and interferes with the β-arrestin2-dependent pathway via G protein-independent mechanisms. TAAR1 is uniquely positioned to exert direct control over DA and 5-HT neuronal firing and release, which has profound implications for understanding the pathophysiology of, and therefore designing more efficacious therapeutic interventions for, a range of neuropsychiatric disorders that involve aminergic dysregulation, including Parkinson's disease, schizophrenia, mood disorders, and addiction. Indeed, the recent development of novel pharmacological tools targeting TAAR1 has uncovered the remarkable potential of TAAR1-based medications as new generation pharmacotherapies in neuropsychiatry. This review summarizes recent developments in the study of TAs and TAAR1, their intricate neurochemistry and pharmacology, and their relevance for neurodegenerative and neuropsychiatric disease.
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Affiliation(s)
| | | | - Juan J. Canales
- Department of Neuroscience, Psychology and Behaviour, University of LeicesterLeicester, UK
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Selective activation of the trace amine-associated receptor 1 decreases cocaine's reinforcing efficacy and prevents cocaine-induced changes in brain reward thresholds. Prog Neuropsychopharmacol Biol Psychiatry 2015; 63:70-5. [PMID: 26048337 DOI: 10.1016/j.pnpbp.2015.05.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/26/2015] [Accepted: 05/26/2015] [Indexed: 01/09/2023]
Abstract
The newly discovered trace amine-associated receptor 1 (TAAR1) has emerged as a promising target for medication development in stimulant addiction due to its ability to regulate dopamine (DA) function and modulate stimulants' effects. Recent findings indicate that TAAR1 activation blocks some of the abuse-related physiological and behavioral effects of cocaine. However, findings from existing self-administration studies are inconclusive due to the very limited range of cocaine unit doses tested. Here, in order to shed light on the influence of TAAR1 on cocaine's reward and reinforcement, we studied the effects of partial and full activation of TAAR1on (1) the dose-response curve for cocaine self-administration and (2) cocaine-induced changes in intracranial self-stimulation (ICSS). In the first experiment, we examined the effects of the selective full and partial TAAR1 agonists, RO5256390 and RO5203648, on self-administration of five unit-injection doses of cocaine (0.03, 0.1, 0.2, 0.45, and 1mg/kg/infusion). Both agonists induced dose-dependent downward shifts in the cocaine dose-response curve, indicating that both partial and full TAAR1 activation decrease cocaine, reinforcing efficacy. In the second experiment, RO5256390 and the partial agonist, RO5263397, dose-dependently prevented cocaine-induced lowering of ICSS thresholds. Taken together, these data demonstrated that TAAR1 stimulation effectively suppresses the rewarding and reinforcing effects of cocaine in self-administration and ICSS models, supporting the candidacy of TAAR1 as a drug discovery target for cocaine addiction.
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Andersen J, Ringsted KB, Bang-Andersen B, Strømgaard K, Kristensen AS. Binding site residues control inhibitor selectivity in the human norepinephrine transporter but not in the human dopamine transporter. Sci Rep 2015; 5:15650. [PMID: 26503701 PMCID: PMC4621520 DOI: 10.1038/srep15650] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 10/01/2015] [Indexed: 02/08/2023] Open
Abstract
The transporters for norepinephrine and dopamine (NET and DAT, respectively) constitute the molecular targets for recreational drugs and therapeutics used in the treatment of psychiatric disorders. Despite a strikingly similar amino acid sequence and predicted topology between these transporters, some inhibitors display a high degree of selectivity between NET and DAT. Here, a systematic mutational analysis of non-conserved residues within the extracellular entry pathway and the high affinity binding site in NET and DAT was performed to examine their role for selective inhibitor recognition. Changing the six diverging residues in the central binding site of NET to the complementary residues in DAT transferred a DAT-like pharmacology to NET, showing that non-conserved binding site residues in NET are critical determinants for inhibitor selectivity. In contrast, changing the equivalent residues in the central site of DAT to the corresponding residues in NET had modest effects on the same inhibitors, suggesting that non-conserved binding site residues in DAT play a minor role for selective inhibitor recognition. Our data points towards distinct structural determinants governing inhibitor selectivity in NET and DAT, and provide important new insight into the molecular basis for NET/DAT selectivity of therapeutic and recreational drugs.
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Affiliation(s)
- Jacob Andersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Kristoffer B Ringsted
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Benny Bang-Andersen
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark.,Lundbeck Research Denmark, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
| | - Anders S Kristensen
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 162, DK-2100 Copenhagen, Denmark
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McHugh PC, Buckley DA. The Structure and Function of the Dopamine Transporter and its Role in CNS Diseases. HORMONES AND TRANSPORT SYSTEMS 2015; 98:339-69. [DOI: 10.1016/bs.vh.2014.12.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Covey DP, Roitman MF, Garris PA. Illicit dopamine transients: reconciling actions of abused drugs. Trends Neurosci 2014; 37:200-10. [PMID: 24656971 DOI: 10.1016/j.tins.2014.02.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/27/2014] [Accepted: 02/05/2014] [Indexed: 01/03/2023]
Abstract
Phasic increases in brain dopamine are required for cue-directed reward seeking. Although compelling within the framework of appetitive behavior, the view that illicit drugs hijack reward circuits by hyperactivating these dopamine transients is inconsistent with established psychostimulant pharmacology. However, recent work reclassifying amphetamine (AMPH), cocaine, and other addictive dopamine-transporter inhibitors (DAT-Is) supports transient hyperactivation as a unifying hypothesis of abused drugs. We argue here that reclassification also identifies generating burst firing by dopamine neurons as a keystone action. Unlike natural rewards, which are processed by sensory systems, drugs act directly on the brain. Consequently, to mimic natural rewards and exploit reward circuits, dopamine transients must be elicited de novo. Of available drug targets, only burst firing achieves this essential outcome.
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Affiliation(s)
- Dan P Covey
- School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - Mitchell F Roitman
- Department of Psychology, University of Illinois at Chicago, Chicago, IL 60607-7137, USA
| | - Paul A Garris
- School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA.
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Davis-MacNevin PL, Dekraker J, LaDouceur L, Holahan MR. Comparison of the MK-801-induced increase in non-rewarded appetitive responding with dopamine agonists and locomotor activity in rats. J Psychopharmacol 2013; 27:854-64. [PMID: 23761388 DOI: 10.1177/0269881113492029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Systemic administration of the noncompetitive N-methyl-D-aspartate (NMDA)- receptor antagonist, MK-801, has been proposed to model cognitive deficits similar to those seen in patients with schizophrenia. Evidence has shown that MK-801 increases the probability of operant responding during extinction, possibly modeling perseveration, as would be seen in patients with schizophrenia. This MK-801-induced behavioral perseveration is reversed by dopamine receptor antagonism. To further explore the role of dopamine in this behavioral change, the current study sought to determine if the MK-801-induced increase in non-rewarded operant responding could be mimicked by dopamine agonism and determine how it was related to locomotor activity. Male Long Evans rats were treated systemically with MK-801, cocaine, GBR12909 or apomorphine (APO) and given a single trial operant extinction session, followed by a separate assessment of locomotor activity. Both MK-801 (0.05 mg/kg) and cocaine (10 mg/kg) significantly increased responding during the extinction session and both increased horizontal locomotor activity. No dose of GBR-12909 (5, 10 or 20 mg/kg) was found to effect non-rewarded operant responding or locomotor activity. APO (0.05, 0.5, 2 or 5 mg/kg) treatment produced a dose-dependent decrease in both operant responding and locomotor activity. These results suggest the possibility that, rather than a primary influence of increased dopamine concentration on elevating bar-pressing responses during extinction, other neurotransmitter systems may be involved.
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Velázquez-Sánchez C, Ferragud A, Ramos-Miguel A, García-Sevilla JA, Canales JJ. Substituting a long-acting dopamine uptake inhibitor for cocaine prevents relapse to cocaine seeking. Addict Biol 2013; 18:633-43. [PMID: 22741574 DOI: 10.1111/j.1369-1600.2012.00458.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The treatment of cocaine addiction remains a challenge. The dopamine replacement approach in cocaine addiction involves the use of a competing dopaminergic agonist that might suppress withdrawal and drug craving in abstinent individuals. Although it has long been postulated that such an approach may be therapeutically successful, preclinical or clinical evidence showing its effectiveness to prevent relapse is scant. We used in rats a procedure that involved substitution of the N-substituted benztropine analog 3α-[bis(4'-fluorophenyl)methoxy]-tropane (AHN-1055), a long-acting dopamine uptake inhibitor (DUI), for cocaine. Maintenance treatment was self-administered. After extinction, reinstatement of drug seeking was induced by cocaine priming. We measured the contents of brain-derived neurotrophic factor (BDNF), c-Fos and Fas-associated death domain (FADD) proteins in the medial prefrontal cortex (mPFC) following reinstatement. DUI, but not amphetamine, substitution led to extinction of active lever presses, as did saline substitution. DUI substitution significantly reduced cocaine-induced reinstatement of drug-seeking behavior, which was strongly elicited after saline substitution. Rats passively yoked to DUI also showed reduced cocaine-primed reinstatement. Reductions in drug seeking during reinstatement were matched by downward shifts in the contents of BDNF, c-Fos and FADD proteins in the mPFC, which were elevated in relapsing rats. These data indicate that DUI substitution not only leads to extinction of self-administration behavior but also prevents reinstatement of drug seeking induced by cocaine re-exposure. Thus, DUI substitution therapy using compounds with low abuse potential, even if received passively in the context previously paired with drug taking, may provide an effective treatment for stimulant addiction.
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Velázquez-Sánchez C, García-Verdugo JM, Murga J, Canales JJ. The atypical dopamine transport inhibitor, JHW 007, prevents amphetamine-induced sensitization and synaptic reorganization within the nucleus accumbens. Prog Neuropsychopharmacol Biol Psychiatry 2013; 44:73-80. [PMID: 23385166 DOI: 10.1016/j.pnpbp.2013.01.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 01/25/2013] [Accepted: 01/25/2013] [Indexed: 11/17/2022]
Abstract
Benztropine (BZT) analogs, a family of agents with high affinity for the dopamine transporter have been postulated as potential treatments in stimulant abuse due to their ability to attenuate a wide range of effects evoked by psychomotor stimulants such as cocaine and amphetamine (AMPH). Repeating administration of drugs, including stimulants, can result in behavioral sensitization, a progressive increase in their psychomotor activating effects. We examined in mice the sensitizing effects and the neuroplasticity changes elicited by chronic AMPH exposure, and the modulation of these effects by the BZT derivative and atypical dopamine uptake inhibitor, JHW007, a candidate medication for stimulant abuse. The results indicated that JHW007 did not produce sensitized locomotor activity when given alone but prevented the sensitized motor behavior induced by chronic AMPH administration. Morphological analysis of medium spiny neurons of the nucleus accumbens revealed that JHW 007 prevented the neuroadaptations induced by chronic AMPH exposure, including increments in dendritic arborization, lengthening of dendritic processes and increases in spine density. Furthermore, data revealed that AMPH produced an increase in the density of asymmetric, possibly glutamatergic synapses in the nucleus accumbens, an effect that was also blocked by JHW007 pretreatment. The present observations demonstrate that JHW007 is able to prevent not only AMPH-induced behavioral sensitization but also the long-term structural changes induced by chronic AMPH in the nucleus accumbens. Such findings support the development and evaluation of BZT derivatives as possible leads for treatment in stimulant addiction.
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Affiliation(s)
- Clara Velázquez-Sánchez
- Behavioural Neuroscience, Department of Psychology, University of Canterbury, Christchurch, New Zealand
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Ahn S, Phillips AG. Daily monitoring of dopamine efflux reveals a short-lasting occlusion of the dopamine agonist properties of d-amphetamine by dopamine transporter blockers GBR 12909 and methylphenidate. ACS Chem Neurosci 2013; 4:817-24. [PMID: 23586444 DOI: 10.1021/cn400040r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
In vivo brain microdialysis was used in conjunction with "reverse-dialysis" of the dopamine-transporter (DAT) blockers GBR 12909 and methylphenidate (MPH) to observe the temporal course of their effects on d-amphetamine (d-AMPH)-induced increases in dopamine (DA) efflux in the rat nucleus accumbens (NAc). Reverse-dialysis of d-AMPH (10 μM) for 30 min resulted in a 2000-2500% increase in DA efflux. Pretreatment with GBR 12909 or MPH (20, 100 μM) for 90 min, which on their own elevated DA levels ∼2000-3000% above baseline values, dose-dependently occluded d-AMPH-evoked DA efflux. In GBR 12909-treated rats, basal levels of DA remained dramatically elevated at 24, 48, and 72 h following treatment, while levels in the MPH group returned back toward pretreatment values. Despite this contrast in basal DA efflux, the magnitudes of DA efflux evoked by a second exposure to d-AMPH were comparable in the two treatment groups. Together, these data support the development of DAT blockers as potential pharmacological interventions for the control of psychostimulant abuse. Furthermore, our data implicate DAT as a common site of action for both GBR 12909 and MPH, as well as d-AMPH.
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Affiliation(s)
- Soyon Ahn
- Department of Psychiatry, University of British Columbia, Vancouver, Canada V6T
2A1
| | - Anthony G. Phillips
- Department of Psychiatry, University of British Columbia, Vancouver, Canada V6T
2A1
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Abstract
Many pharmacological approaches have been used in managing substance use disorders. Conventional pharmacological agents have relatively short durations of action which make them vulnerable to non-adherence and relapse to substance use disorder. To overcome this problem, long-acting preparations have been developed with the aim of reducing the frequency of use and hence improving adherence. This review takes a broad overview of the long-acting preparations available for the management of substance use disorders. The pharmacology, advantages and disadvantages of these preparations are discussed. Many of these preparations hold promise for improving patient outcomes.
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Affiliation(s)
- Aditya Hegde
- Department of Psychiatry, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Reith MEA, Ali S, Hashim A, Sheikh IS, Theddu N, Gaddiraju NV, Mehrotra S, Schmitt KC, Murray TF, Sershen H, Unterwald EM, Davis FA. Novel C-1 substituted cocaine analogs unlike cocaine or benztropine. J Pharmacol Exp Ther 2012; 343:413-25. [PMID: 22895898 DOI: 10.1124/jpet.112.193771] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Despite a wealth of information on cocaine-like compounds, there is no information on cocaine analogs with substitutions at C-1. Here, we report on (R)-(-)-cocaine analogs with various C-1 substituents: methyl (2), ethyl (3), n-propyl (4), n-pentyl (5), and phenyl (6). Analog 2 was equipotent to cocaine as an inhibitor of the dopamine transporter (DAT), whereas 3 and 6 were 3- and 10-fold more potent, respectively. None of the analogs, however, stimulated mouse locomotor activity, in contrast to cocaine. Pharmacokinetic assays showed compound 2 occupied mouse brain rapidly, as cocaine itself; moreover, 2 and 6 were behaviorally active in mice in the forced-swim test model of depression and the conditioned place preference test. Analog 2 was a weaker inhibitor of voltage-dependent Na+ channels than cocaine, although 6 was more potent than cocaine, highlighting the need to assay future C-1 analogs for this activity. Receptorome screening indicated few significant binding targets other than the monoamine transporters. Benztropine-like "atypical" DAT inhibitors are known to display reduced cocaine-like locomotor stimulation, presumably by their propensity to interact with an inward-facing transporter conformation. However, 2 and 6, like cocaine, but unlike benztropine, exhibited preferential interaction with an outward-facing conformation upon docking in our DAT homology model. In summary, C-1 cocaine analogs are not cocaine-like in that they are not stimulatory in vivo. However, they are not benztropine-like in binding mechanism and seem to interact with the DAT similarly to cocaine. The present data warrant further consideration of these novel cocaine analogs for antidepressant or cocaine substitution potential.
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Affiliation(s)
- Maarten E A Reith
- Department of Psychiatry, New York University School of Medicine, 450 E 29th Street, Alexandria Building Room 803, New York, NY 10016, USA.
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Bacterial cocaine esterase: a protein-based therapy for cocaine overdose and addiction. Future Med Chem 2012; 4:137-50. [PMID: 22300094 DOI: 10.4155/fmc.11.194] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Cocaine is highly addictive and there are no pharmacotherapeutic drugs available to treat acute cocaine toxicity or chronic abuse. Antagonizing an inhibitor such as cocaine using a small molecule has proven difficult. The alternative approach is to modify cocaine's pharmacokinetic properties by sequestering or hydrolyzing it in serum and limiting access to its sites of action. We took advantage of a bacterial esterase (CocE) that has evolved to hydrolyze cocaine and have developed it as a therapeutic that rapidly and specifically clears cocaine from the subject. Native enzyme was unstable at 37°C, thus limiting CocE's potential. Innovative computational methods based on the protein's structure helped elucidate its mechanism of destabilization. Novel protein engineering methodologies were applied to substantially improve its stability in vitro and in vivo. These improvements rendered CocE as a powerful and efficacious therapeutic to treat cocaine intoxication and lead the way towards developing a therapy for addiction.
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Oleson EB, Ferris MJ, España RA, Harp J, Jones SR. Effects of the histamine H₁ receptor antagonist and benztropine analog diphenylpyraline on dopamine uptake, locomotion and reward. Eur J Pharmacol 2012; 683:161-5. [PMID: 22445882 DOI: 10.1016/j.ejphar.2012.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 02/22/2012] [Accepted: 03/04/2012] [Indexed: 11/28/2022]
Abstract
Diphenylpyraline hydrochloride (DPP) is an internationally available antihistamine that produces therapeutic antiallergic effects by binding to histamine H₁ receptors. The complete neuropharmacological and behavioral profile of DPP, however, remains uncharacterized. Here we describe studies that suggest DPP may fit the profile of a potential agonist replacement medication for cocaine addiction. Aside from producing the desired histamine reducing effects, many antihistamines can also elicit psychomotor activation and reward, both of which are associated with increased dopamine concentrations in the nucleus accumbens (NAc). The primary aim of this study was to investigate the potential ability of DPP to inhibit the dopamine transporter, thereby leading to elevated dopamine concentrations in the NAc in a manner similar to cocaine and other psychostimulants. The psychomotor activating and rewarding effects of DPP were also investigated. For comparative purposes cocaine, a known dopamine transporter inhibitor, psychostimulant and drug of abuse, was used as a positive control. As predicted, both cocaine (15 mg/kg) and an equimolar dose of DPP (14 mg/kg) significantly inhibited dopamine uptake in the NAc in vivo and produced locomotor activation, although the time-course of pharmacological effects of the two drugs was different. In comparison to cocaine, DPP showed a prolonged effect on dopamine uptake and locomotion. Furthermore, cocaine, but not DPP, produced significant conditioned place preference, a measure of drug reward. The finding that DPP functions as a potent dopamine uptake inhibitor without producing significant rewarding effects suggests that DPP merits further study as a potential candidate as an agonist pharmacotherapy for cocaine addiction.
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Affiliation(s)
- Erik B Oleson
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston Salem, North Carolina, USA
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Cararas SA, Izenwasser S, Wade D, Housman A, Verma A, Lomenzo SA, Trudell ML. Further structure-activity relationship studies on 8-substituted-3-[2-(diarylmethoxyethylidenyl)]-8-azabicyclo[3.2.1]octane derivatives at monoamine transporters. Bioorg Med Chem 2011; 19:7551-8. [PMID: 22055716 PMCID: PMC3230044 DOI: 10.1016/j.bmc.2011.10.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 10/05/2011] [Accepted: 10/10/2011] [Indexed: 11/23/2022]
Abstract
The synthesis and structure-activity relationships of 8-substituted-3-[2-(diarylmethoxyethylidenyl)]-8-azabicyclo[3.2.1]octane derivatives were investigated at the dopamine transporter (DAT), the serotonin transporter (SERT) and norepinephrine transporter (NET). The rigid ethylidenyl-8-azabicyclic[3.2.1]octane skeleton imparted modestly stereoselective binding and uptake inhibition at the DAT. Additional structure-activity studies provided a transporter affinity profile that was reminiscent of the structure-activity of GBR 12909. From these studies, the 8-cyclopropylmethyl group has been identified as a unique moiety that imparts high SERT/DAT selectivity. In this study the 8-cyclopropylmethyl derivative 22e (DAT K(i) of 4.0 nM) was among the most potent compounds of the series at the DAT and was the most DAT selective ligand of the series (SERT/DAT: 1060). Similarly, the 8-chlorobenzyl derivative 22g (DAT K(i) of 3.9 nM) was found to be highly selective for the DAT over the NET (NET/DAT: 1358).
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Affiliation(s)
- Shaine A. Cararas
- Department of Chemistry, University of New Orleans, New Orleans, LA 70148
| | - Sari Izenwasser
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL 33136
| | - Dean Wade
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL 33136
| | - Amy Housman
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, FL 33136
| | - Abha Verma
- Department of Chemistry, University of New Orleans, New Orleans, LA 70148
| | - Stacey A. Lomenzo
- Department of Chemistry, University of New Orleans, New Orleans, LA 70148
| | - Mark L. Trudell
- Department of Chemistry, University of New Orleans, New Orleans, LA 70148
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The atypical stimulant and nootropic modafinil interacts with the dopamine transporter in a different manner than classical cocaine-like inhibitors. PLoS One 2011; 6:e25790. [PMID: 22043293 PMCID: PMC3197159 DOI: 10.1371/journal.pone.0025790] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 09/11/2011] [Indexed: 11/19/2022] Open
Abstract
Modafinil is a mild psychostimulant with pro-cognitive and antidepressant effects. Unlike many conventional stimulants, modafinil has little appreciable potential for abuse, making it a promising therapeutic agent for cocaine addiction. The chief molecular target of modafinil is the dopamine transporter (DAT); however, the mechanistic details underlying modafinil's unique effects remain unknown. Recent studies suggest that the conformational effects of a given DAT ligand influence the magnitude of the ligand's reinforcing properties. For example, the atypical DAT inhibitors benztropine and GBR12909 do not share cocaine's notorious addictive liability, despite having greater binding affinity. Here, we show that the binding mechanism of modafinil is different than cocaine and similar to other atypical inhibitors. We previously established two mutations (W84L and D313N) that increase the likelihood that the DAT will adopt an outward-facing conformational state—these mutations increase the affinity of cocaine-like inhibitors considerably, but have little or opposite effect on atypical inhibitor binding. Thus, a compound's WT/mutant affinity ratio can indicate whether the compound preferentially interacts with a more outward- or inward-facing conformational state. Modafinil displayed affinity ratios similar to those of benztropine, GBR12909 and bupropion (which lack cocaine-like effects in humans), but far different than those of cocaine, β-CFT or methylphenidate. Whereas treatment with zinc (known to stabilize an outward-facing transporter state) increased the affinity of cocaine and methylphenidate two-fold, it had little or no effect on the binding of modafinil, benztropine, bupropion or GBR12909. Additionally, computational modeling of inhibitor binding indicated that while β-CFT and methylphenidate stabilize an “open-to-out” conformation, binding of either modafinil or bupropion gives rise to a more closed conformation. Our findings highlight a mechanistic difference between modafinil and cocaine-like stimulants and further demonstrate that the conformational effects of a given DAT inhibitor influence its phenomenological effects.
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Narasimhan D, Collins GT, Nance MR, Nichols J, Edwald E, Chan J, Ko MC, Woods JH, Tesmer JJG, Sunahara RK. Subunit stabilization and polyethylene glycolation of cocaine esterase improves in vivo residence time. Mol Pharmacol 2011; 80:1056-65. [PMID: 21890748 DOI: 10.1124/mol.111.074997] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
No small-molecule therapeutic is available to treat cocaine addiction, but enzyme-based therapy to accelerate cocaine hydrolysis in serum has gained momentum. Bacterial cocaine esterase (CocE) is the fastest known native enzyme that hydrolyzes cocaine. However, its lability at 37°C has limited its therapeutic potential. Cross-linking subunits through disulfide bridging is commonly used to stabilize multimeric enzymes. Herein we use structural methods to guide the introduction of two cysteine residues within dimer interface of CocE to facilitate intermolecular disulfide bond formation. The disulfide-crosslinked enzyme displays improved thermostability, particularly when combined with previously described mutations that enhance stability (T172R-G173Q). The newly modified enzyme yielded an extremely stable form of CocE (CCRQ-CocE) that retained greater than 90% of its activity after 41 days at 37°C, representing an improvement of more than 4700-fold over the wild-type enzyme. CCRQ-CocE could also be modified by polyethylene glycol (PEG) polymers, which improved its in vivo residence time from 24 to 72 h, as measured by a cocaine lethality assay, by self-administration in rodents, and by measurement of inhibition of cocaine-induced cardiovascular effects in rhesus monkeys. PEG-CCRQ elicited negligible immune response in rodents. Subunit stabilization and PEGylation has thus produced a potential protein therapeutic with markedly higher stability both in vitro and in vivo.
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Affiliation(s)
- Diwahar Narasimhan
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
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Therapeutic-like properties of a dopamine uptake inhibitor in animal models of amphetamine addiction. Int J Neuropsychopharmacol 2011; 14:655-65. [PMID: 20735880 DOI: 10.1017/s1461145710000969] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
N-substituted benztropine (BZT) analogs are molecules that display high affinity for the dopamine transporter (DAT), therapeutic-like effects in animal models of cocaine abuse, and psychopharmacological characteristics consistent with those of a substitute medication for cocaine addiction. Since amphetamine (Amph) and cocaine share mechanisms of action at the DAT, we evaluated the effectiveness of a BZT analog in animal models of Amph addiction. We tested in mice and rats the effects of the BZT derivative, 3α-[bis(4-fluorophenyl)methoxy]-tropane (AHN-1055), on Amph-induced conditioned place preference (CPP), locomotor activity, sensitization, self-administration and ΔFosB accumulation in the nucleus accumbens (NAc). The results showed that AHN-1055 did not produce rewarding, stimulant, or sensitized locomotor effects in mice when administered alone but it readily blocked the rewarding, stimulant, and sensitizing effects of repeated Amph exposure. Furthermore, in mice undergoing conditioning in the CPP paradigm, the BZT analog prevented the accumulation of ΔFosB protein induced in the NAc shell region by Amph treatment. Notably, treatment with AHN-1055 dose-dependently reduced Amph self-administration in rats with a steady history of voluntary Amph intake. These results provide a straightforward demonstration that a BZT derivative with binding affinity for DAT exhibits high efficacy in animal models of Amph abuse, suggesting that the novel generation of BZT analogs could have wider therapeutic applications in stimulant-spectrum disorders than those previously recognized.
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Eriksson O, Långström B, Josephsson R. Assessment of receptor occupancy-over-time of two dopamine transporter inhibitors by [(11)C]CIT and target controlled infusion. Ups J Med Sci 2011; 116:100-6. [PMID: 21443419 PMCID: PMC3078538 DOI: 10.3109/03009734.2011.563878] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
INTRODUCTION Occupancy-over-time was determined for two dopamine transporter (DAT) inhibitors through modeling of their ability to displace the PET ligand [(11)C]CIT. The tracer was held at a pseudo steady state in a reference tissue by target controlled infusion. METHODS Rhesus monkeys (n = 5) were given [(11)C]CIT and studied with a PET scanner. Tracer uptake in the reference tissue cerebellum was held at a pseudo steady state by use of target controlled infusion. The pharmacokinetics/pharmacodynamics(PK/PD) of [(11)C]CIT was assessed through the simplified reference tissue model (SRTM). Bupropion (n = 2) and GBR-12909 (n = 2) receptor occupancies were estimated through modeling of their effects on [(11)C]CIT displacement. RESULTS There was a high uptake of [(11)C]CIT in striatum, which contains a high DAT density. The reference tissue cerebellum had a comparatively low uptake. The modeling of [(11)C]CIT PK/PD properties in striatum showed high binding potential (BP = 5.34 ± 0.78). Both DAT inhibitors caused immediate displacement of [(11)C]CIT after administration. The occupancy-over-time was modeled as a mono-exponential function, describing initial maximal occupancy (Occ(0)) and rate of ligand-receptor dissociation (k(off)). GBR-12909 showed irreversible binding (k(off) = 0) after an initial occupancy of 76.1%. Bupropion had a higher initial occupancy (84.5%) followed by a release half-life of 33 minutes (k(off) = 0.021). CONCLUSIONS The proposed model can be used for assessment of in-vivo occupancy-over-time of DAT ligands by use of target controlled infusion of [(11)C]CIT. The concept of assessing drug-receptor interactions by studying perturbations of a PET tracer from a pseudo steady state can be transferred to other CNS systems.
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Affiliation(s)
- Olof Eriksson
- Department of Radiology, Oncology and Radiation Sciences, Division of Radiology, Uppsala University, Uppsala, Sweden.
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Yorgason JT, Jones SR, España RA. Low and high affinity dopamine transporter inhibitors block dopamine uptake within 5 sec of intravenous injection. Neuroscience 2011; 182:125-32. [PMID: 21402130 DOI: 10.1016/j.neuroscience.2011.03.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 03/03/2011] [Accepted: 03/08/2011] [Indexed: 11/25/2022]
Abstract
Extensive evidence suggests that the reinforcing effects of cocaine involve inhibition of dopamine transporters (DAT) and subsequent increases in dopamine (DA) levels in the striatum. We have previously reported that cocaine inhibits the DAT within 4-5 s of i.v. injection, matching the temporal profile of the behavioral and subjective effects of cocaine. Intravenous injection of GBR-12909, a high affinity, long-acting DAT inhibitor, also inhibits DA uptake within 5 s. Given that high affinity, long-acting drugs are considered to have relatively low abuse potential, we found it intriguing that GBR-12909 had an onset profile similar to that of cocaine. To further explore the onset kinetics of both low and high affinity DAT inhibitors, we examined the effects of i.v. cocaine (1.5 mg/kg), methylphenidate (1.5 mg/kg), nomifensine (1.5 mg/kg), GBR-12909 (1.5 mg/kg), PTT (0.5 mg/kg), and WF23 (0.5 mg/kg) on electrically-evoked DA release and uptake in the nucleus accumbens core. Results indicate that all of the DAT inhibitors significantly inhibited DA uptake within 5 s of injection. However, the timing of peak uptake inhibition varied greatly between the low and high affinity uptake inhibitors. Uptake inhibition following cocaine, methylphenidate, and nomifensine peaked 30 s following injection. In contrast, peak effects for GBR-12909, PTT, and WF23 occurred between 20 and 60 min following injection. These observations suggest that the initial onset for i.v. DAT inhibitors is extremely rapid and does not appear to be dictated by a drug's affinity.
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Affiliation(s)
- J T Yorgason
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
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Rothman RB, Baumann MH, Blough BE, Jacobson AE, Rice KC, Partilla JS. Evidence for noncompetitive modulation of substrate-induced serotonin release. Synapse 2011; 64:862-9. [PMID: 20842720 DOI: 10.1002/syn.20804] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Prior work indicated that serotonin transporter (SERT) inhibitors competitively inhibit substrate-induced [(3)H]5-HT release, producing rightward shifts in the substrate-dose response curve and increasing the EC(50) value without altering the E(max). We hypothesized that this finding would not generalize across a number of SERT inhibitors and substrates, and that the functional dissociation constant (Ke) of a given SERT inhibitor would not be the same for all tested substrates. To test this hypothesis, we utilized a well-characterized [(3)H]5-HT release assay that measures the ability of a SERT substrate to release preloaded [(3)H]5-HT from rat brain synaptosomes. Dose-response curves were generated for six substrates (PAL-287 [naphthylisopropylamine], (+)-fenfluramine, (+)-norfenfluramine, mCPP [meta-chlorophenylpiperazine], (±)-MDMA, 5-HT) in the absence and presence of a fixed concentration of three SERT inhibitors (indatraline, BW723C86, EG-1-149 [4-(2-(benzhydryloxy)ethyl)-1-(4-bromobenzyl)piperidine oxalate]). Consistent with simple competitive inhibition, all SERT inhibitors increased the EC(50) value of all substrates. However, in many cases a SERT inhibitor decreased the E(max) value as well, indicating that in the presence of the SERT inhibitor the substrate became a partial releaser. Moreover, the Ke values of a given SERT inhibitor differed among the six SERT substrates, indicating that each inhibitor/substrate combination had a unique interaction with the transporter. Viewed collectively, these findings suggest that it may be possible to design SERT inhibitors that differentially regulate SERT function.
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Affiliation(s)
- Richard B Rothman
- Clinical Psychopharmacology, IRP, NIDA, NIH, DHHS, Baltimore, Maryland, USA.
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Lin Z, Canales JJ, Björgvinsson T, Thomsen MM, Qu H, Liu QR, Torres GE, Caine SB. Monoamine transporters: vulnerable and vital doorkeepers. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 98:1-46. [PMID: 21199769 PMCID: PMC3321928 DOI: 10.1016/b978-0-12-385506-0.00001-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Transporters of dopamine, serotonin, and norepinephrine have been empirically used as medication targets for several mental illnesses in the last decades. These protein-targeted medications are effective only for subpopulations of patients with transporter-related brain disorders. Since the cDNA clonings in early 1990s, molecular studies of these transporters have revealed a wealth of information about the transporters' structure-activity relationship (SAR), neuropharmacology, cell biology, biochemistry, pharmacogenetics, and the diseases related to the human genes encoding these transporters among related regulators. Such new information creates a unique opportunity to develop transporter-specific medications based on SAR, mRNA, DNA, and perhaps transporter trafficking regulation for a number of highly relevant diseases including substance abuse, depression, schizophrenia, and Parkinson's disease.
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Affiliation(s)
- Zhicheng Lin
- Department of Psychiatry, Harvard Medical School and Division of Alcohol and Drug Abuse, McLean Hospital, Belmont, MA 02478, USA
| | - Juan J. Canales
- Department of Psychology, Behavioural Neuroscience, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Thröstur Björgvinsson
- Behavioral Health Partial Hospital and Psychology Internship Programs, McLean Hospital/Harvard Medical School, Belmont, MA 02478, USA
| | - Morgane M. Thomsen
- Department of Psychiatry, Harvard Medical School and Division of Alcohol and Drug Abuse, McLean Hospital, Belmont, MA 02478, USA
| | - Hong Qu
- Center for Bioinformatics, National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University. Beijing, 100871 China
| | - Qing-Rong Liu
- Behavioral Neuroscience Branch, Intramural Research Program, National Institute on Drug Abuse, NIH/DHHS, 251 Bayview Boulevard, Baltimore, MD 21224, USA
| | - Gonzalo E. Torres
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - S. Barak Caine
- Department of Psychiatry, Harvard Medical School and Division of Alcohol and Drug Abuse, McLean Hospital, Belmont, MA 02478, USA
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Is slow-onset long-acting monoamine transport blockade to cocaine as methadone is to heroin? Implication for anti-addiction medications. Neuropsychopharmacology 2010; 35:2564-78. [PMID: 20827272 PMCID: PMC2978747 DOI: 10.1038/npp.2010.133] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The success of methadone in treating opiate addiction has suggested that long-acting agonist therapies may be similarly useful for treating cocaine addiction. Here, we examined this hypothesis, using the slow-onset long-acting monoamine reuptake inhibitor 31,345, a trans-aminotetralin analog, in a variety of addiction-related animal models, and compared it with methadone's effects on heroin's actions in the same animal models. Systemic administration of 31,345 produced long-lasting enhancement of electrical brain-stimulation reward (BSR) and extracellular nucleus accumbens (NAc) dopamine (DA). Pretreatment with 31,345 augmented cocaine-enhanced BSR, prolonged cocaine-enhanced NAc DA, and produced a long-term (24-48 h) reduction in cocaine self-administration rate without obvious extinction pattern, suggesting an additive effect of 31,345 with cocaine. In contrast, methadone pretreatment not only dose-dependently inhibited heroin self-administration with an extinction pattern but also dose-dependently inhibited heroin-enhanced BSR and NAc DA, suggesting functional antagonism by methadone of heroin's actions. In addition, 31,345 appears to possess significant abuse liability, as it produces dose-dependent enhancement of BSR and NAc DA, maintains a low rate of self-administration behavior, and dose-dependently reinstates drug-seeking behavior. In contrast, methadone only partially maintains self-administration with an extinction pattern, and fails to induce reinstatement of drug-seeking behavior. These findings suggest that 31,345 is a cocaine-like slow-onset long-acting monoamine transporter inhibitor that may act as an agonist therapy for cocaine addiction. However, its pattern of action appears to be significantly different from that of methadone. Ideal agonist substitutes for cocaine should fully emulate methadone's actions, that is, functionally antagonizing cocaine's action while blocking monoamine transporters to augment synaptic DA.
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Velázquez-Sánchez C, Ferragud A, Murga J, Cardá M, Canales JJ. The high affinity dopamine uptake inhibitor, JHW 007, blocks cocaine-induced reward, locomotor stimulation and sensitization. Eur Neuropsychopharmacol 2010; 20:501-8. [PMID: 20413276 DOI: 10.1016/j.euroneuro.2010.03.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 01/12/2010] [Accepted: 03/18/2010] [Indexed: 11/30/2022]
Abstract
The discovery and evaluation of high affinity dopamine transport inhibitors with low abuse liability is an important step toward the development of efficacious medications for cocaine addiction. We examined in mice the behavioural effects of (N-(n-butyl)-3alpha-[bis(4'-fluorophenyl)methoxy]-tropane) (JHW 007), a benztropine (BZT) analogue that blocks dopamine uptake, and assessed its potential to influence the actions of cocaine in clinically-relevant models of cocaine addiction. In the conditioned place preference (CPP) paradigm, JHW 007 exposure did not produce place conditioning within an ample dose range but effectively blocked the CPP induced by cocaine administration. Similarly, in the CPP apparatus JHW 007 treatment failed to stimulate locomotor activity at any dose but dose-dependently suppressed the hyperactivity evoked by cocaine treatment. In locomotor sensitization assays performed in the open field, JHW 007 did not produce sensitized locomotor behaviour when given alone, but it prevented the sensitized component of the locomotor response elicited by subchronic (8-day) cocaine exposure. In the elevated plus maze (EPM), acute treatment with JHW 007, cocaine and combinations of the BZT analogue and cocaine produced an anxiogenic-like profile. Re-test in the EPM following subchronic (8-day) exposure enhanced the anxiogenic-like effect of the same drug treatments. The present findings indicate that JHW 007 exposure counteracts some critical behavioural correlates of cocaine treatment, including conditioned reward, locomotor stimulation and sensitization, and lend support to the further development of BZT analogues as potential replacement medications in cocaine addiction.
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Affiliation(s)
- C Velázquez-Sánchez
- Biopsychology and Comparative Neuroscience Group, Cavanilles Institute (ICBiBE), University of Valencia-FGUV, Valencia, Spain.
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Indarte M, Liu Y, Madura JD, Surratt CK. Receptor-Based Discovery of a Plasmalemmal Monoamine Transporter Inhibitor via High Throughput Docking and Pharmacophore Modeling. ACS Chem Neurosci 2010; 1:223-233. [PMID: 20352074 DOI: 10.1021/cn900032u] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Recognition of psychostimulants such as cocaine and the amphetamines by the dopamine transporter (DAT) protein is principally responsible for the euphoria and addiction associated with these drugs. Using as a template the crystal structure of a distantly related bacterial leucine transporter, 3-D DAT computer molecular models have been generated. Ligand docking to such models has revealed potential substrate and inhibitor binding pockets, subsequently confirmed by in vitro pharmacology. An inhibitor pocket defined by the DAT model to be within the "extracellular vestibule", just to the extracellular side of the external gate of the primary substrate pocket, was used for virtual screening of a structural library of compounds. High-throughput docking and application of pharmacophore constraints within this vestibular inhibitor pocket identified a compound structurally dissimilar to the classic monoamine (dopamine, norepinephrine and serotonin) transporter (MAT) inhibitors. The compound displaced binding of radiolabeled cocaine analogs at all three MATs, usually with nanomolar K(i) values and within two fold of cocaine's affinity at the norepinephrine transporter. Although a very weak dopamine uptake inhibitor itself, this compound reduced by three fold the potency of cocaine in inhibiting DAT-mediated cellular uptake of dopamine. To our knowledge, the present findings are the first to successfully employ "receptor-based" computer modeling to identify moderate-to-high affinity MAT ligands. In silico ligand screening using MAT models provides a rapid, low cost discovery process that should accelerate identification of novel ligand scaffolds and provide lead compounds in combating psychostimulant addiction and in treating other monoamine-related CNS diseases.
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Jupp B, Lawrence AJ. New horizons for therapeutics in drug and alcohol abuse. Pharmacol Ther 2010; 125:138-68. [DOI: 10.1016/j.pharmthera.2009.11.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 11/03/2009] [Indexed: 11/25/2022]
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Ferragud A, Velázquez-Sánchez C, Hernández-Rabaza V, Nácher A, Merino V, Cardá M, Murga J, Canales JJ. A dopamine transport inhibitor with markedly low abuse liability suppresses cocaine self-administration in the rat. Psychopharmacology (Berl) 2009; 207:281-9. [PMID: 19756525 DOI: 10.1007/s00213-009-1653-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Accepted: 08/19/2009] [Indexed: 10/20/2022]
Abstract
RATIONALE N-substituted benztropine analogs are potent dopamine uptake inhibitors that display pharmacokinetic/dynamic properties consistent with the profile of a substitute medication for cocaine addiction. OBJECTIVES The purpose of the present experiments was to characterize in rats the addictive-like properties of one such analog, 3 alpha-[bis(4'-fluorophenyl)methoxy]-tropane (AHN-1055), incorporating probes of its stimulant and incentive/motivational effects and of its ability to influence cocaine self-administration. METHODS We used open field activity and drug self-administration assays. To examine the effects of AHN-1055 on locomotor behavior, the analog was administered alone (0, 1, 3, and 10 mg/kg intraperitoneally) and in combination with cocaine (15 mg/kg i.p.). The influence of AHN-1055 on cocaine's intake was studied by administering the analog (0, 3, and 10 mg/kg i.p.) before the start of the self-administration sessions. To compare the addictive-like properties of AHN-1055 and cocaine, progressive ratio performance and abstinence-induced context-conditioned relapse were evaluated. RESULTS AHN-1055 evoked robust and sustained locomotor activity when administered alone and increased cocaine-induced locomotor stimulation. Notably, the analog showed by comparison to cocaine weak reinforcing efficacy in a modified progressive ratio schedule of drug reinforcement, and contrary to cocaine, it showed no ability to promote context-conditioned relapse to drug seeking following stable self-administration and abstinence. Further, AHN-1055 treatment blocked cocaine intake dose-dependently in rats with a steady history of cocaine self-administration without reducing responding for sucrose, a natural reward. CONCLUSIONS These findings demonstrate essential psychopharmacological differences between AHN-1055 and cocaine and highlight important properties of the analog as a possible pharmacotherapy in cocaine addiction.
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Affiliation(s)
- Antonio Ferragud
- Biopsychology and Comparative Neuroscience Group, Cavanilles Institute (ICBiBE), University of Valencia-General Foundation & Red de Trastornos Adictivos (RETICS), Polígono de la Coma s/n, Paterna, 46980, Valencia, Spain
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